Science 15 EX Goes to Hell The Final Nightmare
If you charge an inflated balloon by rubbing it on your hair and then place the balloon against a wall, it sticks. This is because the charge on the balloon alters the charge distribution in the atoms or molecules in the wall, effectively inducing an opposite charge on the wall. The molecules cannot move from their relatively stationary positions, but their
"centers of charge" are moved.
Chemical batteries or generators are
"electrical pumps" that can maintain a steady flow of charge.
105. Why will the strong man in the previous exercise be more successful in lifting the 10 kg block if he switches places and pushes down on the smaller piston with the block on the larger piston?
-In this case his downward force is multiplied, not divided. He needs only to exert a force equal to one-fiftieth the weight of the 10-kg block. That's 2 N.
Weight density is expressed as
-weight per unit volume.
Celsius The number _ is assigned to the temperature at which water freezes, and the number _ to the temperature at which water boils (at sea-level atmospheric pressure).
0 100
102.Suppose that water is used in a thermometer instead of mercury. If the temperature is 4°C and then changes, why doesn't the thermometer indicate whether the temperature is rising or falling?
0C Freeze 4C and under notmeperature incerase or decfease
Water, like most other substances, expands when heated. But interestingly, it doesn't expand in the temperature range between
0C and 4C
61.Which of these involves the most thermal energy: 1 calorie, 1 Calorie, or 1 joule?
1 Calorie is larger than 1 calorie, which in turn is larger than 1 joule.
1.661×10 minus 24 gram,
1 atomic mass unit is equal to
63.Which raises the temperature of water more: the addition of 1 calorie or of 1 joule?
1 calorie raises the temperature more, since it is the bigger amount of energy.
The net speed, or drift speed, of electrons in a typical circuit is much less than
1 cm/s.
A potential of 1 volt (V) equals
1 joule (J) of energy per 1 coulomb (C) of charge:
They found that if one starts out with a gas, any gas, at 0°C while pressure is held constant, the volume changes by ______ of the original volume for each degree Celsius change in temperature.
1/273
100. Would it be slightly more difficult to draw soda through a straw at sea level or on top of a very high mountain? Explain.
100. It would be harder to suck soda throughh a straw on a very high mountain. This is becaue that when you suck through a straw, its not you pulling on the wtaer, it's atmospheric pressure pushing up on it. When you suck, you are getting rid of air presure in the straw. Atmospheric pressure then moves in in all directions to get that area where the pressur eis at, so it moves inside oif the straw the only way it can, from the bottom. It then pushes up to take all that empty space from the air pressure taken by you and the more you suck on the straw, the more air pressure is taken, and thus, the higher the fluid is pushed. In this case, atmospheric pressure lessens as you get higher in the Earth until eventually it becomes negligible. If you were on a high mountain and were to suck from the straw, atmospheric pressure wouldn't be able to exert as much pressure to push the fluid up as it did when you were on ground level simply because there is less of it.
100.Steel plates are commonly attached to each other with rivets. A rivet is a small metal cylinder, rounded on one end and blunt on the other end. After a hot rivet is inserted in a hole joining the two plates, its blunt end is rounded with a hammer, which is made easier by the hotness of the rivet. How does the hotness of the rivet also help to make a tight fit when it cools?
100. When it cools, it contracts because of what we have learned about thermal expansion. When things get hot, they expand. When they get cold, they contract. This will make the riveter contract itself, and begin pulling on the two plates to try and get smaller. Thus creating a snug and secure fit.
102. Why is it so difficult to breathe when snorkeling at a depth of 1 m, and practically impossible at a depth of 2 m? Why can't a diver simply breathe through a hose that extends to the surface?
102. It's hard to breath with a snorkler at those depths because of atmospheric pressure. The deeper you go, the bigger atmospheric pressure is. In this case, you have a small tube that extends to the surface of the water, when you breath, you are sucking out the air pressure in the tube, which can make the atmospheric pressure crush it. Another thing that could happen is that the pressure outside the tube could be bigger than the pressure inside the tube and crush it or decrease the volume of the tube. You can't just simply breath using a huge hose going to the surface because you will eventually get deep enough to the point where the wate pressure gets so big that it crushes the hose, and now you're at the bottom of the ocean without any air, have fun!
104. In the hydraulic arrangement shown, the larger piston has an area that is 50 times that of the smaller piston. The strong man hopes to exert enough force on the large piston to raise the 10 kg block that rests on the small piston. Do you think he will be successful? Defend your answer.
104. He probably won't be successful. This is because of Pascal's Principle. It states that if a change in pressure occurs in any part of a fluid, that change is transmitted to every part of that fluid. THis means that when our strong friend pushes down on the big piston, he will end up exerting the pressure needed to get to the other side, but that forcewill be transmitted throughout that entire large fluid and divide it when he puts pressure on the big piston, so the pressure will be the same, but the area will get bigger and the force will get smaller when it reacehs the small piston, so chances are, nothing's lifting.
106. Your friend says that the buoyant force of the atmosphere on an elephant is significantly greater than the buoyant force of the atmosphere on a small helium filled balloon. What do you say?-
106. I agree with this because Archimedes' Principle applies to all fluids including air. It states that an object submerged in fluid will be buoyed up by a force equal to the weight of the fluid displaced. In this case, the balloon has a significantly less amount of volume compared to that of the elephant. This means that it will take up less space and therefore displace less air, so the air will buoy up the balloon less than it would buoy up the elephant.
108. A steel tank filled with helium gas doesn't rise in air, but a balloon containing the same gas easily does. Why?
108. The tank has a higher density than the air while the balloon doesn't. This is because when you fill the balloon with helium, you are expanding it and increasing the volume, which in turn decreases the density of both the helium and the balloon itself because the atoms aren't bunched together like they were before they were pushed apart from each other by this inflation. Meanwhile, the tank already is much heavier than the balloon and doesn't expand at all. This makes the tank have a much bigger velocity and therefore not float up in the air no matter how much helium you give it. If anything, the helium is just making the tank barely less dense.
114.How does an airplane adjust its angle of attack so that it is able to fly upside down?
114. The planje would have to adjust it's angle of attack to where the front of the wing is pointing down. This is because when streamlines are closer, speed increases. In order to do that, like the roof of a house, you will need to provide something to block some of the streamlines from moving. This will make them have to get closer to each other in order to get across the wall and not push each other out of the way. This will in turn cause the speed to remain as if you were flying normally.
116.Why is blood pressure measured in the upper arm, at the elevation of your heart?
116. This is because of liquid pressure. When Depth incerases in a fluid, so does pressure, so if you were to go down on your leg, you wold have a much higher blood pressure than your arm.
120.Why can you drink a cup of boiling hot tea atop a high mountain without any danger of burning your lips? What if you did this in a mine shaft below sea level?-
120. When you drink tea from this height, it is high above the ground and thus in an area of lower pressure. This means there is less force pushing the thermal energy particles down. This causes them to spread out more freely, which makes your drink colder. In a deep mine shaft onthe other hand, the tea will be hotter than usual because there is more pressure pushing the thermal energy partiels down, which compresses them and makes them more effectively hotter.
122.A discussion of the following question raises some eyebrows: Why is the buoyant force on a submerged submarine appreciably greater than the buoyant force on it while it is floating?
122. This is because of Archimedes Principle which states that the buoyant force of a body is equal to the weight of the fluid displaced by the body. This means that when the submarine is fully submerged in the water, it displaces as much water as it [possibly can with its volume being as big as possible. This will yield a higher buoyant force. When it is on the surface, it is not fully submerged, so therefore it is not displacing as much water as it can. This will yield a lesser buoyant force.
128.In the classroom demonstration at Lund University, a vacuum pump evacuates air from a large, empty oil drum, which slowly and dramatically crumples as shown. A student friend says that the vacuum sucks in the sides of the drum. What is your explanation?
128. When you suck out the air pressure in the barrel, you are emptying out the pressure that is keeping the atmospheric pressure from crushing the barrel. When it is empty, the atmospheric pressure is greater than the pressure inside the oil can and the barrel gets crushed from the pressure of the atmosphere.
MErcury Density
13.6g/cm^3
56.What is the approximate mass of an oxygen atom in atomic mass units? What is the approximate mass of two oxygen atoms? How about an oxygen molecule?
15.999 kg. 31.998kg
66.Which law of thermodynamics tells us what is most probable in nature?
1st
64.Classify each change as physical or chemical. Even if you are incorrect in your assessment, you should be able to defend why you chose as you did. Grape juice turns to wine. Wood burns to ashes. Water begins to boil. A broken leg mends itself.
1st, a new material is formed from the combination of grape juciea and alchahol. chemicla bond happens. wine made. FERMENTATION WITH ALCHAHOL. 2nd, Combustion is always a chemciql change. Combustion is when oxygen attaches itself to organic materiala nd relaeases fire. 3rd, Water boiling is a physical change. Can be restored. 4th, Your leg mending tho is chemcial. when you break something, that is phsyical.
62.State whether each of the following is a physical or chemical property of matter. Graphite conducts electricity. Bismuth, Bi, loses its iridescence upon melting. A copper penny is smushed into an embossed souvenir.
1st, that is a physical ability it can do. Doesn't change teh propoerties of the atom, just moves electrons form one place to another. No change in charge happens. Gains one, loses one. 2nd, Physical, if you freeze it againm, it will go back ot its original form. CAN BE REVERTED. 3rd, physical change, can be reverted back to oroginal form if needed.
Thus, the melting point of ice is ___ K, and the boiling point of water is ___ K.
273 373
60.As a tree respires, it takes in carbon dioxide, CO2, and water vapor, H2O, from the air, while also releasing oxygen, O2. Does the tree lose or gain weight as it respires? Explain.
372 AMUs get added and 192 AMUs get lost
48.A friend says that molecules in a mixture of gases in thermal equilibrium have the same average kinetic energy. Do you agree or disagree? Defend your answer.
48. I agree. This is because thermal energy is the sum of the total of all kinetic energy in something. Thermal equilibrium on the other hand is when the average kinetic energy per particle in something equals the average kinetic energy per particle in something else. Piecing these two pieces of information together, we come to a conclusion that thermal equilibrium is the sum of the total kinetic energy in something. If you had hot water and doubled the amount of hot water in there, the temperature would still be the same, but the thermal energy and heat would be doubled because the average kinetic energy per particle is still the same.
48.You combine 50 mL of water with 50 mL of purified alcohol and get a total of 98 mL of the mixture. Please explain how this occurs.
48. The alcohol and the waterfall in between the openings of each other are similar to how if you had a bunch of big BB's and put a bunch of small BB's in, they would fill in the openings.
The collapsing effect dominates until the temperature reaches
4°C.
50.A friend tells you that the surface temperature of a particular star is 50,000 degrees. You're not sure whether your friend meant Celsius degrees or kelvins. How much difference is involved in this ambiguity?
50. A lot of difference is in this because the freezing point for Celsius is 0 degrees and the freezing point for fahrenheit is 32 degrees. Also, the boiling point for Celsius is 100 degrees while the freezing point for fahrenheit is 212 degrees.
50.The leftmost diagram below shows the moving particles of a gas within a rigid container. Which of the three boxes on the right—(a), (b), or (c)—best represents this material upon the addition of heat?
50. B because the particles have sped up in that picture and when particles speed up, they are gaining thermal energy, and thus gaining heat. A they are slowing down so if anything theta are getting colder, and C is a different substance all together because the particles are a different size.
54.Which contains the greater amount of thermal energy: an iceberg or a cup of hot coffee? Defend your answer.
54. An iceberg has more thermal energy than the cup of hot coffee. This is because thermal energy is the sum of the total of all kinetic energy in something. This means in this case that since the iceberg has more molecules than the cup of hot coffee, it has more kinetic energy in it. This means that the iceberg has more kinetic energy than the coffee cup. Therefore, it has more thermal energy. Coffee cup has mroe average kinetc energy tho
56.What will be the temperature of a 0°C steel block if its thermal energy is doubled?
546K=273 C
58.Which is heavier: a water molecule, H2O, or a carbon dioxide molecule, CO2?
58. A Carbon dioxide molecule is way heavier than a water molecule. This is because carbon dioxide has carbon and oxygen in it while water has hydrogen and oxygen in it. Carbon has a much higher atomic mass than that of hydrogen.
58.What name is given to "thermal energy in transit"?
58. Heat is thermal energy in transit.
60.What is the general direction of the flow of thermal energy? What is the name of that flow?
60. Hot to Cold. Thermal energy will travel from a high temperature substance to a lower temperature substance. It will keep giving the substance in question thermal energy until either, there is no more thermal energy left to give from the hot substance (which would then be cold) or until the substance is hotter than the original substance. My evidence lies in the 2nd law of Thermodynamics, which states that heat never goes from cold to hot in nature and everything goes from a high quality energy or a lower quality energy and everything goes from order to disorder. This flow from hot to cold is called heat.
62.Which of these involves the least thermal energy: 1 calorie, 1 Calorie, or 1 joule?
62. The least amount of thermal energy is in a joule. This is because one joule is smaller than one calorie. Also, one Calorie equals 1000 calories or 1000 joules.
64.If 100 joules of heat is added to a system that does no external work, by how much is the thermal energy of the system raised?
64. The thermal energy is raised by 100 joules because heat is thermal energy in transit. This basically means that when thermal energy is travelling from one substance to another, it is heat.
68.Under what conditions can thermal energy in a system move from cold to hot?
68. It can move from cold to hot when external work is applied on the system. This is basically saying an outside variable is coming in and changing things forcefully to make the system do what this variable wants it to do. My evidence lies in the 2nd law of Thermodynamics, which states that heat never goes from cold to hot in nature and everything goes from a high quality energy or a lower quality energy and everything goes from order to disorder. This means that naturally, heat will never flow from cold to hot, so logically speaking, external work has to be done on the system to forcibly change the direction of heat,
70.In the previous question, there is a reason why all the gas molecules in our room don't suddenly rush to one corner, leaving us in a vacuum gasping for breath. Does the fact that air naturally spreads out mean that entropy increases or that it decreases?
70. Entropy increases because energy is the measure of energy dispersal in a system. When air spreads out, it goes towards a state of greater disorder, which can be backed up by the 2nd Law of Thermodynamics which states that heat never goes from cold to hot in nature and energy goes from being high quality energy to lower quality energy and everything goes from order to disorder. Also when disorder increases, so does entropy.
70.Snowmaking machines used at ski areas blow a mixture of compressed air and water through a nozzle. The temperature of the mixture may initially be well above the freezing temperature of water, yet crystals of snow are formed as the mixture is ejected from the nozzle. Explain how this happens.
70. This is because when this mixture goes through the small nozzle, it cools. This is because an object will cool when it expands. In this case, when the mixture is in a wide open space and can't expand, it is warm, but when it goes through the nozzle and then expands from there, it is cool.
70. When you squeeze a party balloon between your hands, what happens to the mass of the balloon? To its volume? To its density?
70. When you squeeze a balloon, the mass of it remains the same because mass is the amount of matter in an object. This means that if you were to lower the mass of the balloon, you would have to take a piece off of it or take away some of it's matter, thereby lowering its mass. In this case, you are not doing that and you are just squeezing the atoms of it closer together, so the mass remains the same. The volume lowers because volume is the amount of space an object takes up. If you were to blow a balloon up, it would obviously take up a lot of space, therefore having a lot of volume. If you were to squeeze the balloon, you would be making it smaller because you are pushing the sides of it closer to each other. This will make it take up less space and in turn, make it's volume smaller. Another reason is because volume is inversely proportional to density. This means that when volume goes up, density decreases, and when density increases, volume decreases. This brings us to the density of the balloon. It increases because when volume decreases, density increases. Another reason is that density is the amount of mass per unit volume, basically saying it's the amount of mass per liter or whatever unit for volume you would wish to use. When you blow up a balloon, you stretch it out and therefore, push the atoms of the balloon farther apart from each other. This decreases density because atoms make up matter and the amount of matter in an object is mass and if these atoms are stretched out, there is less matter per unit of volume and thus less mass per unit volume. Therefore, density is decreased.
72.What is the function of an atomic model?
72. They act as a guide to show the inner workings of an atom without actually having to see an atom.
72. The density of a rock doesn't change when it is submerged in water. Does your density change when you are submerged in water? Discuss and defend your answer.
72. Your density does change when you are submerged in water. This is because density is the amount of mass per unit volume or the mass of a section of space. The formula for density is mass divided by volume. This means that if your mass were to go up, your density would increase and if your volume were to go up, your density would go down. Now, if you were to jump in the water, your lungs shrink as you go deeper into the water, this compresses them and makes the volume smalelr, which therfore makes the density beigger.
74.If everything radiates, why doesn't everything zoom downward in temperature?
74. Everything doesn't zoom down in temperature because everything is also an absorber, and as we learned before, hot goes to cold, so that radiated energy goes to a colder substance and is absorbed by it. Basically, it is like money, there is a limited amount of it, but it is traded around.
76.Using as a guide the rule that a good absorber of radiation is a good radiator and the rule that a good reflector is a poor absorber, state a rule relating the reflection and radiation properties of a surface.
76. A good reflector of radiation is a poor radiator and therefore a poor absorber. This is because it will reflect absorbing radiant energy and this will not make it have much energy to radiate.
78.In terms of physics, why do restaurants serve baked potatoes wrapped in aluminum foil?
78. Aluminum foil is a good reflector so it won't absorb much heat emitted by the potato which will cause the heat to stay around inside the foil. This will keep the baked potato warm when it reaches the restaurant patron. Delicious!
78.Which has the greater specific heat capacity: an object that cools quickly or an object of the same mass that cools more slowly?
78. An object that cools more slowly because specific heat capacity is basically thermal inertia. It will resist any changes in temperature whether they be up or down. If it can absorb more heat, then it will take longer to remove a larger amount of heat as well. If an object cools quickly, then there's not much thermal energy in there or there is a lesser resistance in temperature change to it. If it cools slowly however, there is more thermal energy in there and thus there is a greater resistance to temperature change in it, and thus shows us that it has a greater specific heat capacity.
78. What common liquid covers more than two thirds of our planet, makes up 60% of our bodies, and sustains our lives and lifestyles in countless ways?-
78. Water covers more than two thirds of our planet, makes up 60% of our bodies, and sustains life and lifestyles in countless ways.
iron is _ times as dense as water
8
80.On cold winter nights in days past, it was common to take a heated object to bed with you. Which would keep you warmer through the cold night: a 10 kg iron brick or a 10-kg jug of hot water at the same high temperature? Explain.
80. A 10 kg jug of hot water would keep me warmer at night. This is because water has a very high specific heat capacity. This basically means that it is like inertia and resists any change in temperature. It also means that it has to intake a lot more thermal energy to bring it to a specific temperature. This will mean that it will have a lot of thermal energy in it, so it will cool down at a slower rate and will keep you warmer for a longer period of time.
80.Which decreases in temperature more rapidly, a white hot poker or a red-hot poker? Or do they cool at the same rate?-
80. A white hot poker decreases more rapidly because of Newton's LAw of Cooling which states that an object cools at a rate that depends on the difference in temperature between the object and the environment around it. In this case, a white hot poker is hotter than a red hot one which in turn creates a bigger difference in temperature which causes the white hot poker to cool faster.
80. Why is it inaccurate to say that heavy objects sink and that light objects float? Give exaggerated examples to support your answer.
80. If a heavy object had a ridiculously large area, it's pressure and density would be really small. If it was put in the water, the buoyant force of the water would try to equal out the force exerted on it, so it pushes up with that force and overpowers the heavy object and keeps it above the water. If the density was too small compared to the water's density it would also be a reason for being pushed on top of the water. If there was a light object that had an incredibly small area, it's pressure would be close to its original force, and it would have a normal density to how much it weighed. If it had a bigger density than the water and the pressure overpowered the buoyant force, it would sink to the bottom.
An element found in another galaxy exists as two isotopes. If 80.0% of the atoms have an atomic mass of 80.00 atomic mass units, and the other 20.0% have an atomic mass of 82.00 atomic mass units, what is the approximate atomic mass of the element?
80.4 amu
82.If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow only cherry trees and Washington, D.C. only palm trees?
82. For Washington, the wind will be moderated by the ocean and create a moderated climate where the temperature stays the same year round. This is because of Newton's 2nd Law which states that heat never goes from cold to hot in nature and everything goes from a high quality energy or a lower quality energy and everything goes from order to disorder. This means that heat will go from the cold water to the hot air or from the hot water to the cool air. This will create a suitable climate for palm trees. This will be the case because water has a high enough specific heat capacity to distribute enough heat or take enough heat to moderate the climate. Meanwhile, this moderating climate will be taken from San Francisco and the climate will change depending on the season because the wind is blowing away from the city. This will create a more ideal climate to grow cherry trees.
82. A halffilled bucket of water is on a spring scale. Does the reading of the scale increase or remain the same when a fish is placed in the bucket? (Is your answer different if the bucket is initially filled to the brim?)-
82. When a fish is placed in a bucket that is halfway full of water on a spring scale, the reading of the scale would increase. This is because the fish has weight and mass and is added to the bucket of water and its mass will increase the push on the spring scale and thus increase it's reading. If the bucket was filled to the brim with water and a fish was dropped in there, the reading would remain the same because of displacement. Displacement is basically volume getting pushed out of the way when a new volume takes its place. In this case, water equal to the volume of the fish gets pushed out of the cup in order to make room for the fish. This means that the weight of the bucket remains the same unless the fish weighs more or less than the water displaced. This is true if the water falling out of the bucket doesn't land on the spring scale.
84. Why will a block of iron float in mercury but sink in water?
84. A block of iron will float in mercury but not in water because of Archimedes' Principle. It states that an object submerged in fluid will be buoyed up by a force equal to the weight of the fluid displaced. This means that an object submerged in a fluid will be pushed up by a force that is equal to the weight of the fluid displaced. This means that for a fluid like water that is very lightweight, the force of buoyancy is low, but for a fluid like mercury that is a lot more heavyweight, the force of buoyancy will be a lot higher. Weight and volume are independent of each other, so if 2 m of water were displaced and 2 m of mercury were displaced, those 2 m of mercury would weigh more than those 2 m of water.
84.Would a bimetallic strip of two different metals function if each metal had the same rate of expansion? Is it important that the metals expand at different rates? Defend your answer.
84. No it would not, it is very important that the two metals expand at different rates. For example, with brass and iron, the brass expands and contracts at a greater rate than iron. This means that when it contracts, the iron contracts less and this causes the brass to bend the strio in teh direction of itself in order to contract more, or when the brass expands, the iron expands less and in order to expand more, the brass bends in the direction of the iron. If they functioned at the same rate, they would just get smaller or larger, not bend because one doesn't have to bend in order to get smaller or larger.
86.Why are incandescent bulbs typically made of very thin glass?
86. An incandescent lightbulb creates light through being heated. This means that when it is heated, according to heat expansion, the glass of the bulb will expand. This will mean you're gonna want glass that expands a lot so it doesn't create pressure in the bulba jmd cause it to break. Thin glass has a high heat expansion thanks to its low resistance. This will mean that it will expand more and not cause it to break.
50.If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
86. Barium
86. The mountains of the Himalayas are slightly less dense than the mantle material upon which they "float." Do you suppose that, like floating icebergs, they are deeper than they are high?
86. I do believe that the Himalayas, like icebergs, are deeper than they are high. I believe this because when you cut off part of the mountain, it is pushed up to where it gets back close to its original height. This is just like Archimedes' Principle which states that an object submerged in fluid will be buoyed up by a force equal to the weight of the fluid displaced. When part of the mountain gets cut off, the buoyed force is higher than the mountain and pushes it up until it's weight equals the buoyant force again. Just like Archimedes Principle, it balances itself out to follow that rule by being bouye up to match the force of the fluid that it displaced long ago. It's like an ice cube in a drink, it sinks partiatlly. Prinicple of floation, fluid displaces an obejct equal to it;s weight
87.You can determine wind direction by wetting your finger and holding it up in the air. Explain.
87: Where more water evaporates off your finger, the wind is blowing that way
88.Why does a dog pant when it is hot?
88. A dog pants when it is hot because it does not have sweat glands to cool it, so it cools off by panting which triggers evaporation, which is a cooling process, to cool off the dog.
88.An old technique for separating a pair of nested wedged together drinking glasses is to run water at different temperatures into the inner glass and over the surface of the outer glass. Which water should be hot and which cold?
88. The outside glass should be hot and the inside one should be cold. Because of thermal expansion, the hot one will expand and the cold one will contract. This will cause the hot one to expand to create some room for the cold cup and the cold cup will contract and be able to have some wiggle room in the hot cup.
88. The Falkirk Wheel in Scotland (Figure 5.17) rotates with the same low energy no matter what the weight of the boats it lifts. What would be different in its operation if, instead of carrying floating boats, it carried scrap metal that doesn't float?
88. They would have to fill one of the other containers up with enough weight that it could balance out the weight of the scrap metal in the other container. According to Archimedes' Principle which states that an object submerged in fluid will be buoyed up by a force equal to the weight of the fluid displaced, if an object were to be floated to the top by the fluid it displaces, that object floating would have equaled out what was lost when water was displaced. In this case, the weight of the fluid displaced does not equal the weight of the object that did the displacing and it sinks to the bottom, which changes the original weight of the container, so the only way to keep the balance on the wheel intact would be to fill the other container up enough so it can equal the weight of the opposite container. This would be a lot harder, but it would be the only way.
k=
9,000,000,000 N⋅m2/C2.
90.Suppose you cut a small gap in a metal ring. If you heat the ring, does the gap become wider or narrower?
90. The gap becomes wider because of thermal expansion. When you hate that ring, it will expand in all directions equally and thus get bigger, so the gap will be wider when the ring expands.
90. Both a 50 ton boat and a 100-ton boat float side by side in the gondola of the Falkirk Wheel, while the opposite gondola carries no boats at all. Why do the gondolas nevertheless weigh the same?-
90. The reason the two gondolas weigh the same is because of Archimedes' Principle. Archimedes' Principle states that an object that is submerged in fluid will be buoyed up by a force equal to the weight of the fluid displaced. This means that for the two boats in the one gondola, before they were put in the gondola, it was filled to the brim with water. When the two boats were placed in, however, the water in the gondola was displaced by how much space these boats took up. That way, a good deal of the weight of the water was taken away and replaced by the weight of the two boats which balances out the gondola like nothing was ever put in there.
94. How does the density of air in a deep mine compare with the air density at Earth's surface?
94. The density of air in a deep mine compared to the density on the surface of Earth is greater. This is because of Boyle's Law, which states that the product of pressure and volume is the same for a confined gas as long as the temperature doesn't change. This means that if the volume or pressure were to increase or decrease, the other of the two would do the exact opposite. For example, If the volume were to decrease, the pressure would increase and vice versa. This means for our question that the volume in a deep cave is less than the volume on the surface of the Earth, this means that the pressure of air will be bigger in the cave than the surface of the Earth. This in turn means that the density will be bigger in the cave because volume is inversely proportional to density, so if it were to decrease, density would increase. This means that the volume is smaller in the cave and hence, the air is denser there than the surface of Earth. Boyle's Law also shows for this problem that since pressure is greater underground, so is density because when pressure increases, so does density.
96.The temperature of the Sun's interior is about 107. Does it matter whether this is degrees Celsius or kelvins? Defend your answer.
96. It matters whether the temperature is celsius or Kelvin because if the temperature were 10^7 degrees celsius, that would be obnoxiously higher than it being Kelvin. The formula for changing celsius to kelvin after all is adding 273 to the temperature. This would mean that 1 degree celsius is much more than 1 kelvin, and therefore cause a much bigger temperature difference if the sun was 10^7 degrees celsius over 10^7 Kelvin.
98.Structural groaning and creaking noises are sometimes heard in the attic of old buildings on cold nights. Give an explanation in terms of thermal expansion.
98. When it gets cold at night, the boards in your house will start to contract due to thermal expansion going down. Inside expand
89.Give two reasons why pouring a cup of hot coffee into a saucer results in faster cooling?
9: more surface area (more room for evaporation). less mass (less thermal transfer)
A _______ doesn't supply electrons to a circuit; it instead supplies energy to electrons that already exist in the circuit.
A battery
19.What was Planck's quantum hypothesis?
A beam of light consists of zillions of small, discrete packets of energy. Each packet is called a quantum.
91.Why does wrapping a bottled beverage in a wet cloth at a picnic often produce a cooler bottle than placing the bottle in a bucket of cold water?
A bottle wrapped in wet cloth will cool by the evaporation of liquid from the cloth. As evaporation progresses, the average temperature of the liquid left behind in the cloth can easily drop below the temperature of the cool water that wet initially. So to cool a bottled beverage at a picnic, wet a piece of cloth in a bucket of cool water, then wrap it around the bottle. As evaporation progresses, the temperature of the water in the cloth drops, and cools the bottle to a temperature below that of the water in the bucket.
Periodic table
A chart in which all known elements are listed in order of atomic number.
Atomic number
A count of the number of protons in the atomic nucleus.
Spectroscope
A device that uses a prism or diffraction grating to separate light into its color components.
it is usually provided by an electric switch that can be opened or closed to either cut off energy or allow energy to flow
A gap
77.Which undergoes a greater change in temperature when heat is applied: 1 kg of water or 1 kg of iron? Defend your answer.
A greater change in temperature occurs for iron because it has a smaller specific heat capacity.
Period
A horizontal row in the periodic table.
79.People often behave differently when they are in a group than when they are by themselves. Explain how this is similar to the behavior of atoms. Is this good news or bad news for the development of nanotechnology?
A macroscopic sample of an element contains billions upon billions of atoms bunched together. The properties exhibited by these grouped atoms are not necessarily the same as the properties of the atoms when isolated individually or in smaller groupings. Individual gold atoms, for example, appear red—not gold—and single sheets of graphite are transparent—not black. This is good news for nanotechnology because it means there are many nanoscopic properties yet to be discovered and exploited.
85."A calculator is useful but certainly not exciting." Why would someone from 100 years ago vehemently disagree with this statement? We often marvel at a new technology, but how long does this marveling last? How soon before a new technology becomes assumed? Think of other examples. Is technology the source of happiness?
A new technology seems to maintain its marvel for several years and then the appeal begins to fade. Instead of marveling at this technology, people then come to expect it. This happened when plastics were first introduced in the 1940s and 50s. Plastics were known as a wonder material. Now we do our best to recycle plastics so they don't pollute our roadways and overfill our garbage dumps. Life is no doubt more comfortable and convenient with our warm GoreTex jackets and cell phones. But are we necessarily happier? Many think that happiness arises from within the person. To them it is no surprise that comfort and convenience beyond that which is necessary for our basic needs does little to improve one's sense of well-being.
15.What is the difference between a physical model and a conceptual model?
A physical modes attempts to replicate an object at a different scale. A conceptual model describes a system.
Proton
A positively charged subatomic particle of the atomic nucleus.
Shell
A region of space about the atomic nucleus within which electrons may reside.
Conceptual model
A representation of a system that helps us predict how the system behaves.
Physical model
A representation of an object on some convenient scale.
First law of thermodynamics
A restatement of the law of energy conservation, usually as it applies to systems involving changes in temperature: the heat added to a system is equal to the system's gain in thermal energy plus the work that it does on its surroundings.
73. You know that a sharp knife cuts better than a dull knife. Do you know why this is so? Defend your answer.
A sharp knife cuts better than a dull knife because it has a thinner cutting area which results in more cutting pressure for a given force.
Quantum
A small, discrete packet of light energy.
elemental makeup.
A star's age is revealed by its
t requires a suitable pumping device to maintain a difference in electric potential to maintain a voltage.
A sustained electric curren
95. The "pump" in a vacuum cleaner is merely a high speed fan. Would a vacuum cleaner pick up dust from a rug on the Moon? Explain.-
A vacuum cleaner wouldn't work on the Moon. A vacuum cleaner operates on Earth because the atmospheric pressure pushes dust into the machine's region of reduced pressure. On the Moon there is no atmospheric pressure to push the dust anywhere.
93.Erik Wong crunches an aluminum soft drink can on page 180. Is the can sucked in by the partial vacuum created, or pushed inward by atmospheric pressure? Or both?-
A vacuum is a condition of nothingness, which cannot suck the can inward. The vacuum, even partial, allows the outside atmosphere to exert a net force on the walls of the can, which causes the sudden crunch. So it is not "both."
Group
A vertical column in the periodic table, also known as a family of elements.
66.Each sphere in the diagrams below represents an atom. Joined spheres represent molecules. Which box contains a liquid phase? Why can't you assume that box B represents a lower temperature?
A> Gas phase because theya re taking up the whole box. B> In liquid/solid phase. HARD TO TELL. Can't say tehre was phase change becasue the 2nd box has new compounds, so that means they arent tyhe same. Prob same temp because there are still spome floating that are on thjeir own in the2nd box.
The temperature at which no further energy can be taken from a system.
Absolute zero
111.Your friend says that more thermal energy is needed to increase a gram of water from absolute zero to its boiling point than is needed to boil the water once it reaches 100°C. Do you agree or disagree?
Agree, for along the way from absolute zero to boiling water, you encounter 334 J in changing phase from ice to water, but a whopping 2256 J to change the water to steam. The energies in raising ice and water temperatures along the way aren't enough to overcome this difference
92.A friend says that the reason why you feel uncomfortable in muggy weather is that water molecules in the air are giving up energy while bombarding you. Do you agree or disagree with your friend?
Agree. water loses energy by condensing on your skin condensation warms your skin. water loses energy and that energy transfers to your skin. also lesser rate of evaporation..
115.The photo shows physics teacher Marshall Ellenstein walking barefoot on broken glass bottles in his class. What physics concept is Marshall demonstrating, and why is he careful to ensure that the broken pieces are small and numerous? (The Band
Aids on his feet are for humor!)-The concept of pressure is being demonstrated. He is careful that there are numerous small pieces of glass so that his weight is applied over a large contact area so that the sharp glass provides insufficient pressure to cut his feet.
69.When you blow air onto your hand from your wide open mouth, your hand is warmed. Why is your hand cooled if you pucker your lips when blowing?-
Air cools when it expands. Expansion is minimal when blown from your wide-open mouth, but is greater when exiting the smaller opening with puckered lips. The cooled breath cools your hand.
96. It is said that a gas fills all the space available to it. Why, then, doesn't the atmosphere go off into space?
Air has weight which means gravity is pushing down on it. This weight is called atmospheric pressure.
92.How does the combined volume of the billions of hexagonal open spaces in the structures of ice crystals in a piece of ice compare with the portion of ice that floats above the water line?
Air pockets both have them
mercury, Hg; gallium, Ga; cesium, Cs; and francium, Fr hydrogen, H
All but a few metals are solid at room temperature. The exceptions are _______, which are all liquids at a warm room temperature of 30°C (86°F). Another interesting exception is ________
72.The source of the heat of volcanoes and natural hot springs is trace amounts of radioactive minerals in common rock in Earth's interior. Why isn't the same kind of rock at Earth's surface warm to the touch?
All that radiant energy is held in by the Earth's crust like a cooler that is made to keep something warm. Anything can block radiation. When it's on the surface, it emits all tat energy and now its not warm
69.Oxygen atoms are used to make water molecules. Does this mean that oxygen, O2, and water, H2O, have similar properties? Why do we drown when we breathe in water, despite all the oxygen atoms present in this material?
All the oxygen water present is bound to hydrogen atoms making water molecules. Water is uniquely different from the elements oxygen, O2, and hydrogen, H2, from which it can be made. The oxygen our bodies are designed to breathe is gaseous molecular oxygen, O2. We drown when we breathe in water because it contains so little O2. Although they both contain oxygen, gaseous oxygen, O2, and water, H2O, are vastly different materials.
46.Is chemistry the study of submicroscopic, microscopic, or macroscopic matter, or of all three? Defend your answer.
All three because you are studying matter and how it is made so you need to know it inside and out.
Electric current that repeatedly reverses its direction; the electric charges vibrate about relatively fixed points. In the United States, the vibration rate is 60 Hz.
Alternating current (ac)
indirectly.
Although we cannot see atoms directly, we can generate images of them ______
The unit of electric current; the rate of flow of 1 coulomb of charge per second.
Ampere
Ohm discovered that the amount of current in a circuit is directly proportional to the voltage established across the circuit and is inversely proportional to the resistance of the circuit: Current=voltageresistance Or, in units form,
Amperes=volts/ohms
Atomic symbol
An abbreviation for an element or atom.
write the mass number as a superscript and the atomic number as a subscript to the left of the atomic symbol.
An alternative method of indicating isotopes is to
Neutron
An electrically neutral subatomic particle of the atomic nucleus.
23.About how fast does an electron travel around the atomic nucleus?
An electron moves around the nucleus at around 2 million meters per second.
Electron
An extremely small, negatively charged subatomic particle found outside the atomic nucleus.
Max Planck (1858-1947)
An important step toward our present understanding of atoms and their spectra was taken by the German physicist
Principal quantum number n
An integer that specifies the quantized energy level of an atomic orbital.
78.How does a scanning probe microscope differ from an optical microscope?
An optical microscope is a microscope where you see something with your own eyes using a magnifying glass. A Scanning probe microscope is a microscope where you see something by seeing an image created by a needle being dragged across an atom.
Element
Any material that is made up of only one type of atom.
Isotopes
Any member of a set of atoms of the same element whose nuclei contain the same number of protons but different numbers of neutrons.
67.How does buoyancy play a role in the rising of a parcel of warm air?
Any parcel of air displaces its own volume of surrounding air. If the parcel is warmed it expands and becomes less dense than the surrounding air. Since it displaces a greater weight of air than its own weight, it is buoyed upward.
Nucleon
Any subatomic particle found in the atomic nucleus. Another name for either a proton or a neutron.
Research that focuses on developing applications of knowledge gained through basic research.
Applied research
-An immersed body is buoyed up by a force equal to the weight of the fluid it displaces (for both liquids and gases).
Archimedes' principle
alkaline earth metals.
As a holdover from these ancient times, group 2 elements are known as the
53.A skillet is lined with a thin layer of cooking oil followed by a layer of unpopped popcorn kernels. Upon heating, the kernels all pop, thereby escaping the skillet. Identify any physical or chemical changes.
As each kernel is heated, the water within each kernel is also heated to the point that it would turn into water vapor. The shell of the kernel, however, is air tight and this keeps the water as a superheated liquid. Eventually the pressure exerted by the superheated water exceeds the holding power of the kernel and the water bursts out as a vapor, which causes the kernel to pop. These are physical changes. The starches within the kernel, however, are also cooked by the high temperatures, and this is an example of a chemical change.
121.Hydrothermal vents are openings in the ocean floor that discharge water at temperatures far exceeding 100°C. Discuss why this water is not boiling.
As in a pressure cooker, the great pressure on the ocean floor prevents boiling of water at temperatures exceeding 100°C.
75.What particle within an atom vibrates to generate electromagnetic radiation? This particle is vibrating back and forth between what?
As the electron vibrates within the atom it generates electromagnetic wavers. The electron vibrates back and forth between different energy levels.
49.Which has stronger attractions among its submicroscopic particles: a solid at 25°C or a gas at 25°C? Explain.
At 25°C there is a certain amount of thermal energy available to all the submicroscopic particles of a material. If the attractions between the particles are not strong enough, the particles may separate from each other to form a gaseous phase. If the attractions are strong, however, the particles may be held together in the solid phase. We can assume, therefore, that the attractions among the submicroscopic particles of a material in its solid phase at 25°C are stronger than they are within a material that is a gas at this temperature.
-The pressure exerted against bodies immersed in the atmosphere, resulting from the weight of air pressing down from above. At sea level, atmospheric pressure is about 101 kPa.
Atmospheric pressure
5.Distinguish between an atom and an element.
Atom is used to refer to submicroscopic particles in a sample. An element is used for microscopic and macroscopic samples.
If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
Atomic mass, 99 amu; technetium
67.As depicted in Figure 12.19, are gallium atoms really red and arsenic atoms green?
Atoms are colored for organization and difference in characteristics
44.In what sense can you truthfully say that you are a part of every person around you?
Atoms are recyclable, this means that when you lose your atoms, they are used for something else, like to make up a plant, air, fire, other people, etc. Your atoms come from recycled atoms from other people and things. You have part of Einstein's brain, and you have part of Lincoln's brain. We are all made from recycled atoms of other people, places, or things.
never see them in the usual sense
Atoms are so incredibly small that we can ____.
17.What causes an atom to emit light?
Atoms give off light as they are subjected to energy.
-Any device that measures atmospheric pressure.
Barometer
63.Germanium, Ge (atomic number 32), computer chips operate faster than silicon, Si (atomic number 14), computer chips. So how might a gallium, Ga (atomic number 31), chip compare with a germanium chip?
Based upon its location in the periodic table we find that gallium, Ga, is more metallic in character than germanium, Ge. This means that gallium should be a better conductor of electricity. Computer chips manufactured from gallium, therefore, operate faster than chips manufactured from germanium. (Gallium has a low melting point of 30°C, which makes it impractical for use in the manufacture of computer chips. Mixtures of gallium and arsenic, however, have found great use in the manufacture of ultra fast, though relatively expensive, computer chips.)
Research that leads us to a greater understanding of how the natural world operates.
Basic research
positions
Because atoms are invisible, however, we cannot use a physical model to represent them. In other words, we cannot simply scale up the atom to a larger size, as we might with a microorganism. (A scanning probe microscope merely shows the _______ of atoms and not actual images of atoms, which do not have the solid surfaces implied in the scanning probe image of Figure 12.19b.)
alkali metals.
Because of this history, group 1 elements, which are metals, are called the_____
-The pressure in a fluid moving steadily, without friction or external energy input, decreases when the fluid velocity increases.
Bernoulli's principle
45.Of physics, chemistry, and biology, which science is the most complex? Please explain.
Biology is based upon the principles of chemistry as applied to living organisms, while chemistry is based upon the principles of physics as applied to atoms and molecules. Physics is the study of the fundamental rules of nature, which more often than not are rather simple in their design and readily described by mathematical formula. Because biology sits at the top of these three sciences, it can be considered to be the most complex of them all.
130.The snow covered mailboxes raise a question: What explains why the light-colored ones are snow covered, while the black ones are free of snow?-
Black ones emit heat better than white
95.Boiling can be brought about by increasing the temperature of water. How can boiling be brought about without increasing water temperature?
Boiling can be brought about by reducing the air pressure on the water.
59.In the winter Vermonters make a tasty treat called "sugar on snow" in which they pour boiled down maple syrup onto a scoop of clean fresh snow. As the syrup hits the snow, it forms a delicious taffy. Identify the physical changes involved in the making of sugar on snow. Identify any chemical changes.
Boiling down the maple syrup involves the evaporation of water. As the syrup hits the snow it warms the snow causing it to melt while the syrup becomes more viscous. These are all examples of physical changes. Interestingly, as the maple syrup is boiled the sugar within the syrup begins to caramelize, which is an example of a chemical change.
73.Which of the following boxes contains only an element? Which contains only a compound? How many different types of molecules are shown altogether in the three boxes?
Box "a" is a mixture. Box "b": compound. Box "c": element. There are three different types of molecules shown altogether in all three boxes: one with two open circles joined, one with a solid and open circle joined, and one with two solid circles joined.
-The product of pressure and volume is a constant for a given mass of confined gas regardless of changes in either pressure or volume individually, so long as temperature remains unchanged:
Boyle's law
Which element would have chemical properties the most similar to those of chlorine (Cl, atomic number 17)?
Br
101.After a machinist quickly slips a hot, snugly fitting iron ring over a very cold brass cylinder, the two metals cannot be separated intact. Can you explain why this is so?
Brass expands and contracts more than iron for the same changes in temperature. Since they are both good conductors and are in contact with each other, one cannot be heated or cooled without also heating or cooling the other. If the iron ring is heated, it expands—but the brass expands even more (greater a). Cooling the two will not result in separation either, for even at the lowest temperatures the shrinkage of brass over iron would not produce separation. So the two metals cannot be separated.
-The net upward force that a fluid exerts on an immersed object.
Buoyant force
What happens in a barometer is similar to what happens when you drink through a straw.
By sucking, you reduce the air pressure in the straw when it is placed in a drink. Atmospheric pressure on the drink then pushes the liquid up into the reduced-pressure region. Strictly speaking, the liquid is not sucked up; it is pushed up the straw by the pressure of the atmosphere.
65.Strontium, Sr (atomic number 38), is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues (calcium, Ca, atomic number 20). How is this fact related to what you know about the organization of the periodic table?
Calcium is readily absorbed by the body for the building of bones. Since calcium and strontium are in the same atomic group they have similar physical and chemical properties. The body, therefore, has a hard time distinguishing between the two and strontium is absorbed just as though it were calcium.. Strontium is similar to calcium. When you drink milk, it puts the components of it where you need it. Done by characteristics of particular atoms. Only problem is when two elements are similar so human body can get confused and can put strontium in your bones NOT GOOD.
anotehr name for kilocalorie
Calorie
53.Which has more atoms: a 1-gram sample of carbon-12 or a 1-gram sample of carbon-13? Explain.
Carbon-13 atoms have more mass than carbon-12 atoms. Because of this, a given mass of carbon-13 contains fewer atoms than the same mass of carbon-12. Look at it this way—golf balls have more mass than Ping-Pong balls. So, which contains more balls: 1 kilogram of golf balls or 1 kilogram of Ping-Pong balls? Because Ping-Pong balls are so much lighter, you need many more of them to get 1 kilogram.
Kelvin temperature divisions are identical to the divisions on the
Celsius Scale
The force of attraction between two atoms that holds them together.
Chemical bond
The formation of new substance(s) by rearranging the atoms of the original material(s).
Chemical change
A notation that indicates the composition of a compound, consisting of the atomic symbols for the different elements of the compound and numerical subscripts indicating the ratio in which the atoms combine.
Chemical formula
Any property that characterizes the ability of a substance to change into a different substance under specific conditions.
Chemical property
A term synonymous with chemical change.
Chemical reaction
The study of matter and the transformations it can undergo.
Chemistry
89.In 2011, China was the leading producer of rare-earth metals, such as neodymium. controlling about 95% of the market. When China then tried to take financial advantage of this near-monopoly, it didn't work. Why not?
China had been selling rare-Earth metals for so cheap for so many years that mines within other nations were forced to close. As soon as China started placing high export taxes on these metals, other nations were led to re-invest in their closed mines. To open a mine can take several years, which is only about as long as China was able to take advantage of its situation.
6.What is the atomic symbol for the element cobalt?
Co
114.Friends in your discussion group say that when you touch a piece of ice, cold "flows" from the ice to your hand, which is why your hand is cooled. What is your more enlightened response?
Cold does not flow from your ice to your hand. Thermal energy rather transfers from your hand to the ice cube. Hence why the ice cube melts, because the thermal energy it gained is melting it.
A material in which atoms of different elements are bonded to one another.
Compound
Any material having free charged particles that easily flow through it when an electric force acts on them.
Conductor
99.When boiling spaghetti, is your cooking time reduced if the water is vigorously boiling instead of gently boiling?
Cooking time will be no different for vigorously boiling water and gently boiling water, for both have the same temperature. The reason spaghetti is cooked in vigorously boiling water is simply to ensure the spaghetti doesn't stick to itself and the pot. For fuel economy, stir your spaghetti in gently boiling water.
The SI unit of electric charge. One coulomb (symbol C) is equal in magnitude to the total charge of 6.25 × 1018 electrons.
Coulomb
Two charged objects that are much smaller than the distance between them experience a force that varies directly as the product of their charges and inversely as the square of their separation distance. If the charges are alike in sign, the force is repelling; if the charges are unlike, the force is attractive.
Coulomb's law
So Newton's law of gravitation for masses is similar to
Coulomb's law for electrically charged bodies.
87.If matter is made of atoms, and atoms are made of subatomic particles, what comes together to create subatomic particles? Where might you find such information?
Curious? You would need to research this on your own as we need to draw the line somewhere of what to cover and not to cover in this textbook. Briefly, in the same way that Rutherford was able to deduce the atomic nucleus by bombarding atoms with alpha particles, evidence for the existence of even smaller subatomic particles has been obtained by bombarding the atom with highly energetic radiation. This research over the past century has evolved into what is known as the "standard model of fundamental particles" which places all constituents of matter within one of two categories: quarks and leptons. There are six quarks and they have the whimsical names: up, down, charm, strange, top, and bottom. The proton is made of two up quarks and one down quark, while the neutron is made of two down quarks and one up quark. There are six leptons and they all appear to be point-like particles without internal structure. The best-known lepton is the electron.
________ is a flow of charge, pressured into motion by voltage and hampered by resistance.
Current
Ohm's Law Formula
Current=voltage/resistance A current of 1 A is produced by a potential difference of 1 V across a resistance of 1 Ω.
120.Compared to an empty ship, would a ship loaded with a cargo of Styrofoam sink deeper or less deeply into water? Discuss and defend your answer.
Deeper because p[rinciple of floation says that floating objects hgave boyyant force equal to weight of object. This jeans that the force will be bigger. The thing is, the only way to do that is by increasing the boyhant force. The boyant force is created by the wieght of water dispalecd as stated by Archimedes Principle. this means that the boat will sink more to solve that
-The amount of matter per unit volume:
Density
-Density formula
Density=massvolume
An electric current that flows in one direction only.
Direct current (dc)
49.A friend says that molecules in a mixture of gases in thermal equilibrium have the same average speed. Do you agree or disagree? Defend your answer.
Disagree, for having the same KE does not mean having the same speed, unless all gas molecules have equal masses.
The flow of electric charge that transports energy from one place to another.
Electric current
The electric potential energy per amount of charge, measured in volts; often called voltage.
Electric potential
The energy a charge possesses by virtue of its location in an electric field.
Electric potential energy
The rate of energy transfer, or the rate of doing work; the amount of energy per unit time, which can be computed as the product of current and voltage:
Electric power
The property of a material that resists the flow of an electric current through it. It is measured in ohms (Ω).
Electrical resistance
Term applied to an atom or molecule in which the charges are aligned in such a way that one side has a slight excess of positive charge and the other side a slight excess of negative charge.
Electrically polarized
probability clouds and atomic orbitals
Electron waves are three-dimensional, which makes them difficult to visualize, but scientists have come up with ways of visualizing them. This include
A notation that uses the atomic symbol and (sometimes) a numerical subscript to denote how many atoms are bonded in one unit of an element.
Elemental formula
46.The air we breathe is not considered by chemists to be an element. Why not?
Elements are any type of material that is made of only 1 type of atom. When we breathe, the atoms of our breath are spread out throughout the world and mix with the air we breathe. We are breathing in other people's breaths.
7.What role does atomic number play in the periodic table?
Elements are listed in the periodic table in order of increasing atomic number.
halogens ("salt forming" in Greek)
Elements of group 17 are known as the
75.What is the name given to radiant energy emitted by Earth? How does it differ from radiation emitted by the Sun?
Energy emitted by Earth is called terrestrial radiation. It differs only in frequency from radiation emitted by the Sun. Most radiation emitted by the Sun is of higher frequency.
The change in the thermal energy of a system plus the product of its pressure and volume.
Enthalpy
The measure of energy dispersal of a system. Whenever energy freely transforms from one form to another, the direction of transformation is toward a state of greater disorder and, therefore, toward one of greater entropy.
Entropy
52.A cotton ball is dipped in alcohol and wiped across a tabletop. Explain what happens to the alcohol molecules deposited on the tabletop. Is this a physical or chemical change?
Evaporate after killing germs. Physical change. Whenever there is a phase change, it's physical
57.Red Kool Aid crystals are added to a still glass of water. The crystals sink to the bottom. Twentyfour hours later, the entire solution is red even though no one stirred the water. Explain.
Even though the water appears to be still, the water molecules are bustling with kinetic energy. The red dye of the Kool-aid gets knocked around by these molecules to the point that the dye is eventually dispersed throughout the water. This is another case where the existence of molecules helps to explain the observed phenomenon.
More than two centuries ago, America's first great scientist, Benjamin Franklin, did similar experiments. He formed the following hypotheses:
Every neutral (uncharged) substance has its own appropriate level of electric fluid.
89.A metal ball is barely able to pass through a metal ring. When Anette Zetterberg heats the ball, it does not pass through the ring. What happens if she instead heats the ring (as shown)? Does the size of the hole increase, stay the same, or decrease?
Every part of a metal ring expands when it is heated—not only the thickness, but the outer and inner circumference as well. Hence the ball that normally passes through the hole when the temperatures are equal will more easily pass through the expanded hole when the ring is heated. (Interestingly, the hole will expand as much as a disk of the same metal undergoing the same increase in temperature. Blacksmiths mounted metal rims on wooden wagon wheels by first heating the rims. Upon cooling, the contraction resulted in a snug fit.)
77.You enter a crowded and chilly classroom early in the morning on a cold winter day. Before the end of the hour, the room temperature increases to a comfortable level, even if heat is not provided by the school heating system. Why the difference?
Every student radiates about the same amount of heat as a 100-W incandescent bulb. So heat radiated by you and your classmates increases the temperature of the room.
Coulomb's law can be expressed as
F=k q1q2
shell model
For the purposes of a simplified understanding of how atoms behave, we turn to the
Linus Pauling (1901-1994).
For the purposes of a simplified understanding of how atoms behave, we turn to the shell model, first made popular by the noted chemist and two- time Nobel laureate
57.What is the approximate mass of a carbon atom in atomic mass units? How about a carbon dioxide molecule?
From the periodic table we see that a carbon atom has a mass of about 12 amu. The carbon dioxide molecule, CO2, consists of one carbon atom bonded to two oxygen atoms for a total mass of about 44 amu.
The proportionality constant k in Coulomb's law is similar to
G in Newton's law of gravity. Instead of being a very small number, like G, k is a very large number, approximately
51.Why would you expect the molecules in a gas to have a variety of speeds?
Gas molecules continually collide with one another, sometimes giving to and sometimes receiving kinetic energy from neighbors. In this continual interaction, it would be statistically impossible for any large number of molecules to have the same speed. Temperature has to do with average speeds.
71.What happens to the gas pressure within a sealed gallon can when it is heated? When it is cooled? Defend your answers.
Gas pressure increases in the can when heated, and decreases when cooled. The pressure that a gas exerts depends on the average kinetic energy of its molecules, therefore, on its temperature.
56.Alcohol wiped across a tabletop rapidly disappears. What happens to the temperature of the tabletop? Why?
Get colder. Evaporation is a cooling process
70.Oxygen, O2, is certainly good for you. Does it follow that if small amounts of oxygen are good for you, then large amounts of oxygen would be especially good for you?
Getting too much oxygen will cause headaches, nausa, and for too much for a while: death. All things in moderation
noble gas properties
Group 18 elements are all unreactive gases that tend not to combine with other elements.
noble gases,
Group 18 elements are all unreactive gases that tend not to combine with other elements. For this reason, they are called the
1.Which is the oldest element?
H
74.What is the chemical formula for the compound dihydrogen sulfide?
H2S
The thermal energy that flows from a substance of higher temperature to a substance of lower temperature, commonly measured in calories or joules.
Heat
Formula for the first law of thermodynamics
Heat added =increase in the system's energy+ external work done by the system
83.Compared with conventional water heaters in the United States, why do propane tankless water heaters (which are common in other parts of the world) cost up to 60% less to operate?
Heat loss from storage tanks adds to the cost of providing hot water. Tank-less water heaters use energy on demand to heat water, and have no storage tanks that undergo heat loss with time.
Second law of thermodynamics
Heat never spontaneously flows from a cold substance to a hot substance. Also, in natural processes, high-quality energy tends to transform into lower-quality energy—order tends to disorder.
110.For water, which has the higher value: heat of fusion or heat of vaporization?
Heat of vaporaization 54
61.Which will cool your finger faster, touching a nail stuck in ice or touching the surface of the ice? Explain.
Heat will conduct from your warm finger to the cold ice either way, but faster through the nail because it is more conducting than snow.
massive collections of hydrogen atoms pulled together by gravitational forces.
Heavier atoms are produced in stars, which are
99.Why is it important that glass mirrors that have a low "coefficient of expansion" be used in astronomical observatories?
High expansion rate would mean greater difference in shape with different temperature, which would be a liability for a telescope mirror.
54.A cotton ball dipped in alcohol is wiped across a tabletop. Would the resulting smell of the alcohol be more or less noticeable if the tabletop were much warmer? Explain.
Hotter=Evaporate. More particles in the air, stronger the smell
103.If cooling occurred at the bottom of a pond instead of at the surface, would a lake freeze from the bottom up? Explain.
If cooling occurred at the bottom of a pond instead of at the surface, ice could still form at the surface, but it would take much longer for ponds to freeze. This is because all the water in the pond would have to be reduced to a temperature of 0°C rather than 4°C before the first ice would form. Ice that forms at the bottom where the cooling process occurs would be less dense and would float to the surface (except for ice that may form on material anchored to the bottom of the pond).
83.If the composition of the atmosphere were changed so that it permitted a greater amount of terrestrial radiation to escape, what effect would this have on Earth's climate?
If more terrestrial radiation in the atmosphere escaped, Earth's climate would be cooler.
73.Why does adding the same amount of heat to two different objects of the same mass not necessarily produce the same increase in temperature?
If the different objects are of different substances, with different specific heat capacities, then they'll have their own characteristic changes in temperature when equal quantities of heat are applied. Only if the two objects have the same specific heat capacities will the temperature changes be the same.
85.In terms of thermal expansion, why is it important that a lock and its key be made of the same material or of similar materials?
If they expanded differently, as for different materials, the fit between the lock and key wouldn't match.
117.How do the average kinetic energies of hydrogen and oxygen gases compare when these two gases are mixed at the same temperature? How do the average speeds of their molecules compare? Discuss how mass is the crux of these questions.
If they have the same temperature, then by definition, they have the same average kinetic energies per molecule. But the hydrogen, with less mass, has the higher speed (½mV2 = ½Mv2, where V > v).
118.In a mixture of U 238 and U-235 isotopes, which atoms have the greater average speed? How would this affect diffusion through a porous membrane of otherwise identical gases made from these isotopes? Link this to the previous question.-
If they have the same temperature, then by definition, they have the same average kinetic energies per molecule. But the hydrogen, with less mass, has the higher speed (½mV2 = ½Mv2, where V > v).
111.How will two dangling vertical sheets of paper move when you blow between them? Try it and see.
In accord with Bernoulli's principle, the sheets of paper will move inward together because air pressure between them is reduced, and will be less than the air pressure on the outside surfaces.
With this broader perspective, the second law can be stated another way:
In natural processes, high-quality energy tends to transform into lower-quality energy—order tends to disorder.
scanning probe microscope
In the mid-1980s, researchers developed the _____, which produces images by dragging an ultrathin needle back and forth over the surface of a sample. Bumps the size of atoms on the surface cause the needle to move up and down.
51.The leftmost diagram below shows two phases of a single substance. In the middle box, draw what these particles would look like if heat were taken away. In the box on the right, show what they would look like if heat were added. If each particle represents a water molecule, what is the temperature of the box on the left?
In the middle box you should have drawn all the particles aligned with each other as is seen in the left side of the first box. This would indicate the solid phase. In the box on the right, you should have drawn all the particles in random places as is seen in the right side of the first box. This represents the liquid phase. If each one of these particles represented a water molecule, the first box on the left would be indicative of ice melting, which occurs at 0°C.
115.If all the molecules in a liquid had the same speed, and some were able to evaporate, would the remaining liquid be cooled? Explain.
In this hypothetical case evaporation would not cool the remaining liquid because the energy of exiting molecules would be no different than the energy of molecules left behind. Although thermal energy of the liquid would decrease with evaporation, energy per molecule would not change. No temperature change of the liquid would occur. (The surrounding air, on the other hand, would be cooled in this hypothetical case. Molecules flying away from the liquid surface would be slowed by the attractive force of the liquid acting on them.)
81.Why does the presence of large bodies of water tend to moderate the climate of nearby land, making it warmer in cold weather and cooler in hot weather?
In winter months when the water is warmer than the air, the air is warmed by the water to produce a seacoast climate warmer than inland. In summer months when the air is warmer than the water, the air is cooled by the water to produce a seacoast climate cooler than inland. This is why seacoast communities and especially islands do not experience the high and low temperature extremes that characterize inland locations.
A system for naming the countless number of possible compounds has been developed by the
International Union of Pure and Applied Chemistry (IUPAC).
desnest material on Earth
Irdium
Whatever the system—be it a steam engine, Earth's atmosphere, or the body of a living creature—heat added to it can have two effects.
It can increase the system's thermal energy, or it can enable the system to do work on its surroundings (or both).
84.Use the shell model to explain why a potassium atom, K, is larger than a sodium atom, Na.
It has more electrons than sodium, so therefore there will be more shells to hold these more electrons, which will result in a bigger atom due to the addition of more shells and empty space between them.
43.If someone is able to explain an idea to you using small familiar words, what does this say about how well that person understands the idea?
It is easy to hide a lack of understanding by using big words you know others are not familiar with. If you have truly mastered a concept, you should be able to explain that concept to others using a language that is familiar to you both.
131.Invoking ideas from Chapter 2 and this chapter, discuss why is it easier to throw a curve with a tennis ball than with a baseball.
It si easier to throw a curve ball with a ennis ball because it hass less inertia. This means it will r3esist the turning less. The turinging is caused by the spin of the ball. It grabs a streamline and turns it with it and cerates a low pressure area on the side it will curve on.
57.What will be the temperature of 0°C helium gas if its thermal energy is halved?
It will be half 273 K, which is 136.5 K or 2136.5 °C.
69.Why is it not possible for a scanning probe microscope to make images of the inside of an atom?
It's made of atoms so you can't put atoms inside of otehr atoms
55.On which temperature scale does the average kinetic energy of molecules double when the temperature doubles?
Kelvin
79.Why isn't it important to convert temperatures to the Kelvin scale when we use Newton's law of cooling?
Kelvins and Celsius degrees are the same size. Although ratios of these two scales will produce very different results, differences in kelvins and differences in Celsius degrees will be the same. Since Newton's law of cooling involves temperature differences, either scale may be used.
96.Why does the boiling temperature of water decrease when the water is under reduced pressure, such as at a higher altitude?
Less presure holding the water particles together
Once these charges have been assigned, we can see the most fundamental rule of electrical behavior:
Like charges repel; opposite charges attract.
74.What does the high specific heat of water have to do with the convection currents in the air at the seashore?
Low pressure to high
Guideline 3
Many compounds are not usually referred to by their systematic names. Instead, they are assigned common names that are more convenient or have been used traditionally for many years. Some common names are water for H2O, ammonia for NH3, and methane for CH4.
81.Medicines, such as pain relievers and antidepressants, are found in the drinking water supplies of many municipalities. How did these medicines get there? Does it matter that they are there? Should something be done about it? If so, what?
Many medicines are flushed down drains or toilets directly or after already having passed through the human body an into the urine. These drugs then end up in downstream water supplies. By the time they reach the downstream consumer their concentration is at a relatively low level. But this level is easily measured. Perhaps of greatest concern is the effect these low doses might have over the long term. Drinking a single glass of drug tainted water might not have a noticeable effect. But what if this water is consumed by an individual over his or her life time?
71.Would you use a physical model or a conceptual model to describe the following: a gold coin, a dollar bill, a car engine, air pollution, a virus, the spread of sexually transmitted disease?
Many objects or systems may be described just as well by a physical model as by a conceptual model. In general, the physical model is used to replicate an object or system of objects on a different scale. The conceptual model, by contrast, is used to represent abstract ideas or to demonstrate the behavior of a system. Of the examples given in the exercise the following might be adequately described using a physical model: a gold coin, a car engine, and a virus. The following might be adequately described using a conceptual model: a dollar bill (which represents wealth but is really only a piece of paper), air pollution, and the spread of a sexually transmitted disease.
quantized
Mass and electric charge are therefore said to be________ in that they consist of some number of fundamental units.
9.Distinguish between mass number and atomic mass.
Mass number is the count of nucleons in an isotope. Atomic mass is a measure of the total mass of an atom.
is anything that occupies space
Matter
malleable;ductile
Metals are _______, which means they can be hammered into different shapes or bent without breaking. They are also _____, which means they can be drawn into wires.
Properties of metals
Metals are malleable, which means they can be hammered into different shapes or bent without breaking. They are also ductile, which means they can be drawn into wires. All but a few metals are solid at room temperature. The exceptions are mercury, Hg; gallium, Ga; cesium, Cs; and francium, Fr, which are all liquids at a warm room temperature of 30°C (86°F). Another interesting exception is hydrogen, H, which takes on the properties of a liquid metal only at very high pressures (Figure 12.10). Under normal conditions, hydrogen behaves like a nonmetallic gas. shiny, opaque, and good conductors of electricity and heat
An extremely small fundamental structure built of atoms.
Molecule
127.Earth scientists are considering a means of inducing clouds to be a brighter white. What effect would this have on Earth's climate?
More solar energy would be reflected into space, cooling Earth's surface beneath. (Whitening clouds is a consideration in offsetting the warming by excess carbon dioxide.)
77. If water faucets upstairs and downstairs are turned fully on, does more water per second flow out the downstairs faucet? Or is the volume of water flowing from the faucets the same?
More water will flow from a downstairs open faucet because of the greater pressure. Since pressure depends on depth, the downstairs faucet is effectively "deeper" than the upstairs faucet. The pressure downstairs is greater by an amount = weight density × depth, where the depth is the vertical distance between faucets.
beginning of our universe about 13.7 billion years ago
Most of these hydrogen atoms were formed during the
112.Wrap part of a fur coat around a thermometer. Discuss whether or not the temperature rises.
NO CHANGE. A coat is an insulator and slows the transfer of thermal energy from one thing to another. So if thermometer is in thermal equilubiruj with oustide envirment, it won't change temp with coat around it. When wearing coat outside when hot, your body creates tehrmal energy continously and you can't release it so you bburn up
The manipulation of individual atoms or molecules.
Nanotechnology
85.Neon, Ne (atomic number 10), cannot attract any additional electrons. Why?
Neon's outermost shell is already filled to capacity with electrons. Any additional electrons would have to occupy the next shell out where the electrical attraction from the atomic nucleus is much weaker.
_______ is easier to handle than liquid helium, which is needed for creating colder conditions.
Nitrogen
2.Is it possible to see an atom using visible light?
No
Third law of thermodynamics
No system can reach absolute zero.
109.Air conditioning units contain no water whatsoever, yet it is common to see water dripping from operating outdoor air conditioners on homes on a hot day. Explain.-
No water leaks from inside the unit, for the dripping water is water vapor in the air that has condensed on the cold coolant tubes.
40.If all the molecules of a body remained part of that body, would the body have any odor?
No you smell an odor from particles leaving something. When in a bathroom, you are inhaling poop particles when it smells bad in there. It would not because you are constantly emitting atoms from your body that go around the world. Your breath on it's own is inhaled by everybody. This would include atoms that are part of you that have a distinct smell to them. Your armpits when smelly emit atoms that give that odor.
21.Did Bohr think of his planetary model as an accurate representation of what an atom looks like?
No, Bohr's model merely illustrated the different energy levels of an electron in an atom.
119.A number of objects at different temperatures placed in a closed room share radiant energy and ultimately come to the same temperature. Would this thermal equilibrium be possible if good absorbers were poor emitters and poor absorbers were good emitters? Defend your answer.
No. If good absorbers were not also good emitters, then thermal equilibrium would not be possible. If a good absorber only absorbed, then its temperature would climb above that of poorer absorbers in the vicinity. And if poor absorbers were good emitters, their temperatures would fall below that of better absorbers.
119.If liquid pressure were the same at all depths, would there be a buoyant force on an object submerged in the liquid? Discuss your explanation with your friends.
No. The reason for a bouyant force is because pressure is depth dependent, This means that pressure is the gretaest on the bottom of all bodies. This in turn means that water pressure will push up on it the most which is the bouyant force. This is because pressure in a fluid is exeretd equallyin all directons at any point. If the presure was the same everywhere, there wpuld be no higher pressure pushing up, so you would have no bouyantforce
The current in a circuit varies in direct proportion to the potential difference or voltage and inversely with the resistance:
Ohm's law
did hemisshpere experiminet
Otto von Guericke
77.What is the common name for oxygen oxide?
Oxygen, O2.
-Formula for Boyle's law
P1V1=P2V2
List the following atoms in order of increasing atomic size: thallium, Tl; germanium, Ge; tin, Sn; phosphorus, P.
P<Ge<Sn<Tl
An electric circuit with two or more devices connected in such a way that the same voltage acts across each one, and any single one completes the circuit independently of all the others.
Parallel circuit
103. Say you've had a run of bad luck, and you slip quietly into a small, calm pool as hungry crocodiles lurking at the bottom are relying on Pascal's principle to help them to detect a tender morsel. What does Pascal's principle have to do with their delight at your arrival?
Part of whatever pressure you add to the water is transmitted to the hungry crocodiles, via Pascal's principle. If the water were confined, that is, not open to the atmosphere, the crocs would receive every bit of pressure you exert. But even if you were able to slip into the pool to quietly float without exerting pressure via swimming strokes, your displacement of water raises the water level in the pool. This ever-so-slight rise, and accompanying ever-so-slight increase in pressure at the bottom of the pool, is an eversowelcome signal to the hungry crocodiles. Yum! Yum!
-A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid.
Pascal's principle
A change in a substance's physical properties, with no change in its chemical identity.
Physical change
Any physical attribute of a substance, such as color, density, or hardness.
Physical property
63.State whether each of the following is a physical or chemical property of matter. Carbon dioxide escapes when a soda can is opened. A bronze statue turns green. A silver spoon tarnishes.
Physical property: a; Chemical property: b, c
Would you use a physical model or a conceptual model to describe the following, respectively: the brain; the mind; the solar system; the beginning of the universe?
Physical; conceptual; physical; conceptual
The difference in potential between two points, measured in volts; often called voltage difference.
Potential difference
Electric power is equal to the product of current and voltage:*
Power=current×voltage
Electric Power Formula
Power=current×voltage It is measured in watts (or kilowatts), where 1 A × 1 V = 1 W.
-The ratio of force to the area over which that force is distributed:
Pressure
-A floating object displaces a weight of fluid equal to its own weight
Principle of flotation
62.A beam of protons and a beam of neutrons of the same energy are both harmful to living tissue. The beam of neutrons, however, is less harmful. Suggest why.
Protons have a charge. Particles passing and charged particles pasisng which damages is coimon sense
55.Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom's size?
Protons, which are nearly 2000 times more massive than electrons, contribute much more to the mass of an atom. Protons, however, are held within the atomic nucleus, which is only a tiny tiny fraction of the volume of the atom. The size of the atom is spelled out by the electrons, which sweep through a relatively large volume of space surrounding the nucleus.
44.What is the best way to really prove to yourself that you understand an idea?
Put it into application in real life situations.
Formula for specific heat capacity
Q=c*m*ΔT
a number of distinct energy levels
Rather, within the atom there must be_________, analogous to steps on a staircase.
78.Which color of light comes from a greater energy transition: red or blue?
Red because the redder something gets, the higher the frequency and in turn, the greater energy transition.
The equivalent resistance Req of a circuit consisting of several resistors is the sum of the values for the individual resistors. For number of resistors n in series, then,
Req=R1+R2+R3+⋯Rn
Members of the American Chemistry Council, who produce 90% of the chemicals manufactured in the United States, have adopted a program called
Responsible Care, in which they have pledged to manufacture without causing environmental damage.
101. Richard's pump can operate at a certain maximum well depth in Pocatello, Idaho. Would this maximum depth be greater than, less than, or the same as if he pumps water in San Francisco?
Richard's pump operates by way of atmospheric pressure. The greater the atmospheric pressure on the surface of water in the well, the deeper the well can be. Since atmospheric pressure is greater in sea-level San Francisco than in higher-altitude Pocatello, maximum well depth for Richard's pump is greater in San Francisco.
79.Desert sand is very hot in the day and very cool at night. What does this tell you about its specific heat?
Sand has a low specific heat, as evidenced by its relatively large temperature changes for small changes in thermal energy. A substance with a high specific heat, on the other hand, must absorb or release large amounts of thermal energy for comparable temperature changes.
A tool of nanotechnology that detects and characterizes the surface atoms of materials by way of an ultrathin probe tip, which is detected by laser light as it is mechanically dragged over the surface.
Scanning probe microscope
47.Are elements made of atoms or are atoms made of elements?
Scientists tend to refer to an element as a material made of only one kind of atom. They may be referring to a bulk quantity. A block of pure silicon, for example, contains nothing but silicon atoms. They may also be referring to a submicroscopic quantity. For example, they may say that the element silicon reacts with the element oxygen to form a new material called silicon dioxide, SiO2. In such a case, silicon and oxygen atoms combine in a 1:2 ratio.
An electric circuit with devices connected in such a way that the current is the same in each device.
Series circuit
53.Which is greater: an increase in temperature of 1°C or an increase of 1°F?
Since Celsius degrees are larger than Fahrenheit degrees, an increase of 1 C° is larger, actually 9/5 as large.
properties of metalloids
Situated between the metals and the nonmetals in the periodic table, the metalloids have both metallic and nonmetallic characteristics.
boron, B; silicon, Si; germanium, Ge; arsenic, As; antimony, Sb; and tellurium, Te.
Six elements are classified as metalloids:
conceptual model
So, rather than describing the atom with a physical model, chemists use what is known as a
The quantity of heat required to raise the temperature of a unit mass of a substance by 1°C.
Specific heat capacity
The realm of atoms and molecules, where objects are too small to be detected by optical microscopes.
Submicroscopic
82.Why is a water based white solution (whitewash) sometimes applied to the glass of florists' greenhouses? Would you expect this practice to be more prevalent in the winter or in the summer?-
Summer. This solution helps reflect radiation. Reflects the heat away from the greenhouse so the plants don't overheat.
Any material with zero electrical resistance, wherein electrons flow without losing energy and without generating heat.
Superconductor
A measure of the hotness of substances, related to the average translational kinetic energy per molecule in a substance, measured in degrees Celsius, degrees Fahrenheit, or kelvins.
Temperature
61.Each night you measure your height just before going to bed. When you arise each morning, you measure your height again and consistently find that you are 1 inch taller than you were the night before, but only as tall as you were 24 hours ago! Is what happens to your body in this instance best described as a physical change or a chemical change? Be sure to try this activity if you haven't already.
That this process is so reversible suggests a physical change. As you sleep in a reclined position, pressure is taken off of the discs within your spinal column, which allows them to expand so that you are significantly taller in the morning. Astronauts returning from extended space visits may be up to two inches taller upon their return.62. They are all examples of physical properties.
81.Which will warm by 15°C quicker in a 100°C oven: a 10°C piece of pie or a 20°C piece of pie?
The 10°C piece of pie will warm faster because, in accord with Newton's law of cooling, ΔT (100°C − 10°C) with its surroundings is greater than for the 20°C piece of pie.
47.You combine 50 mL of small BBs with 50 mL of large BBs and get a total of 90 mL of BBs of mixed sizes. Please explain how this occurs.
The 50 mL plus 50 mL do not add up to 100 mL because within the mix, many of the smaller BB's are able to fit within the pockets of space that were empty within the 50 mL of large BB's.
60.Oxygen, O2, has a boiling point of 90 K (−183°C), and nitrogen, N2, has a boiling point of 77 K (−196°C). Which is a liquid and which is a gas at 80 K (−193°C)?
The Oxygen is a liquid at room temperature because it has not reached its boiling point so therefore it cannot evaporate into gas form and it is cool enough to liquify. The nitrogen is a gas at this point because it has boiled and turned itself into a gas because the temperature is past its boiling point.
59.When we breathe we inhale oxygen, O2, and exhale carbon dioxide, CO2, plus water vapor, H2O. Which probably has more mass: the air that we inhale or the same volume of air that we exhale? Does breathing cause you to lose or gain weight?
The air we exhale is somewhat more massive than the air we inhale because it contains a greater proportion of the heavier carbon dioxide molecules. Interestingly, the added water vapor in our exhaled breath is less massive than the oxygen that it replaced, but not enough to counteract the much greater mass of the carbon dioxide. Breathing causes you to lose weight.
Why are the atomic masses listed in the periodic table not whole numbers?
The atomic masses are average atomic masses.
93.A piece of solid iron sinks in a container of molten iron. A piece of solid aluminum sinks in a container of molten aluminum. Why does a piece of solid water (ice) not sink in a container of "molten" (liquid) water? Explain, using molecular terms.
The atoms and molecules of most substances are more closely packed in solids than in liquids. So most substances, such as iron, aluminum, and most all metals, are denser in the solid phase than in the liquid phase. Water is different. In the solid phase the structure is open-spaced and ice is less dense than water. Hence ice floats in water.
13.If a baseball were the size of Earth, about how large would its atoms be?
The atoms in the baseball would be the size of Ping Pong balls if the baseball were the size of Earth.
41.Where did the atoms that make up a newborn baby originate?
The atoms that make up a newborn baby or anything else in this world originated in the fires of ancient stars.
123.A balloon is weighted so that it is barely able to float in water. If it is pushed beneath the surface, does it rise back to the surface, stay at the depth to which it is pushed, or sink? Discuss your explanation. (Hint: Does the balloon's density change?)
The balloon will sink to the bottom because its density increases with depth. The balloon is compressible, so the increase in water pressure beneath the surface compresses it and reduces its volume, thereby increasing its density. Density is further increased as it sinks to regions of greater pressure and compression. This sinking is understood also from a buoyant force point of view. As its volume is reduced by increasing pressure as it descends, the amount of water it displaces becomes less. The result is a decrease in the initial buoyant force that was sufficient to barely keep it afloat.
101.In the power plant of a nuclear submarine, the temperature of the water in the reactor is above 100°C. How is this possible?
The boiling point of water is higher in a nuclear reactor because of increased pressure. The reactor behaves like a pressure cooker.
91. A ship sailing from the ocean into a fresh water harbor sinks slightly deeper into the water. Does the buoyant force on it change? If so, does it increase or decrease?-
The buoyant force does not change. The buoyant force on a floating object is always equal to that object's weight, no matter what the fluid.
81. Why does an inflated beach ball pushed beneath the surface of water swiftly shoot above the water surface when released?
The buoyant force on the ball beneath the surface is much greater than the force of gravity on the ball, producing a large net upward force and large acceleration.
43.Where did the carbon atoms in Leslie's hair originate? (Shown below is a photo of coauthor Leslie at 16.)
The carbon atoms that make up coauthor Leslie's hair or anything else in this world originated in the fires of ancient stars. How so is explored in Chapter 13.
39.A cat strolls across your backyard. An hour later, a dog with its nose to the ground follows the trail of the cat. Explain what is going on from a molecular point of view.
The cat leaves a trail of molecules across the yard. These molecules leave the ground and mix with the air, where they enter the dog's nose, activating the sense of smell.
67.Is aging primarily an example of a physical or chemical change?
The changes that occur as we age involve the chemical reformation of our biomolecules. These are chemical changes.
Atomic nucleus
The dense, positively charged center of every atom.
71. A can of diet soft drink floats in water, whereas a can of regular soft drink sinks. Discuss this phenomenon first in terms of density, then in terms of weight versus buoyant force.
The diet drink is less dense than water, whereas the regular drink is denser than water. (Water with dissolved sugar is denser than pure water.) Also, the weight of the diet can is less than the buoyant force that would act on it if totally submerged. So it floats, where buoyant force equals the weight of the can.
81.Some older cars vibrate loudly when driving at particular speeds. For example, at 65 mph the car may be most quiet, but at 60 mph the car may rattle uncomfortably. How is this analogous to the quantized energy levels of an electron in an atom?
The dimensions of the car and the nature of the materials of the car dictate that there will be certain frequencies that reinforce themselves upon vibration. When the vibration of the tires matches the car's "natural frequency" the result is a resonance, which is are self-reinforcing waves. The wave nature of the car, however, is simply due to the back and forth vibrations of the materials of the car. The wave nature of the electron, on the other hand, is entirely different. For the electron moving a very high speeds, some of its mass is converted to energy, which is manifest in its wave nature. Given the dimensions of the atom, certain frequencies of the electron will also be "natural", that is, self-reinforcing. The vibrating car, therefore, is analogous to one of the energy levels of the electron, which is the point at which the electron forms a self-reinforcing standing wave.
transition metals
The elements of groups 3 through 12 are all metals that do not form alkaline solutions with water. These metals tend to be harder than the alkali metals and less reactive with water; hence they are used for structural purposes. Collectively they are known as the _____, a name that denotes their central position in the periodic table.
109.Two identical balloons of the same volume are pumped up with air to more than atmospheric pressure and suspended on the ends of a stick that is horizontally balanced. One of the balloons is then punctured. Is there a change in the stick's balance? If so, which way does it tip?
The end supporting the punctured balloon tips upwards as it is lightened by the amount of air that escapes. There is also a loss of buoyant force on the punctured balloon, but that loss of upward force is less than the loss of downward force, since the density of air in the balloon before puncturing was greater than the density of surrounding air.
113.What is the principal reason why a feather quilt is so warm on a cold winter night?
The feather quilt is an excellent insulator (poor conductor due to trapped air), which slows the transfer of heat from your body to the surroundings.
79. How much force is needed to push a nearly weightless but rigid 1L carton beneath a surface of water?-
The force needed will be the weight of 1 L of water, which is 9.8 N. If the weight of the carton is not negligible, then the force needed would be 9.8 N minus the carton's weight, for then the Earth would be 'helping' to force the carton down.
73.What does the formula f ~ T tell us about what radiates and what doesn't?
The formula tells us that any object with any temperature is continually emitting radiant energy.
89. One gondola in the Falkirk Wheel carries a 50 ton boat, while the opposite gondola carries a 100-ton boat. Why do the gondolas nevertheless weigh the same?-
The gondolas weigh the same because they're brim full, and whatever the weight of a floating boat, that same weight of water was displaced when the boat entered the gondola.
73.What is the relationship between the light emitted by an atom and the energies of the electrons in the atom?
The greater the frequency of a photon of light, the greater the energy packed into that photon.
71.From a position near an incandescent lamp, turn it on and off quickly. While it is briefly on you feel its heat, but when you touch the bulb, you find that it is not hot. Explain why you felt heat from the lamp.
The heat you received was from radiation, which travels at the speed of light. Heating the glass, however, is a longer process.
99. If you could somehow replace the mercury in a mercury barometer with a denser liquid, would the height of the liquid column be greater or less than with mercury? Why?
The height would be less. The weight of the column balances the weight of an equal-area column of air. The denser liquid would need less height to have the same weight as the mercury column.
97.If you drop a hot rock into a pail of water, the temperature of the rock and that of the water change until both are equal. The rock cools and the water warms. Does this hold true if the hot rock is dropped into the Atlantic Ocean? Defend your answer.
The hot rock will cool and the cool water will warm, regardless of the relative amounts of each. The amount of temperature change, however, does depend in great part on the relative masses of the materials. For a hot rock dropped into the Atlantic Ocean, the change in water temperature would be too small to measure. If you kept increasing the mass of the rock or kept decreasing the mass of the ocean, a change would eventually be evident.
107. When you replace helium in a balloon with hydrogen, which is less dense? Does the buoyant force on the balloon change if the balloon remains the same size? Explain.
The hydrogen-filled balloon is less dense. The buoyant force does not change because the volume of the balloon does not change. The buoyant force is the weight of air displaced, and doesn't depend on what is doing the displacing. The net upward force (BF − mg) is, however, greater on the lighter hydrogen balloon.
Quantum hypothesis
The idea that light energy is contained in discrete packets called quanta.
51.The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?
The iron atom is electrically neutral when it has 26 electrons to balance its 26 protons.
Atomic mass
The mass of an element's atoms listed in the periodic table as an average value based on the relative abundance of the element's isotopes.
103.How do the temperature at which a particular metal melts and the temperature at which it freezes compare?
The melting and freezing temperatures are the same.
Guideline 1
The name of the element farther to the left in the periodic table is followed by the name of the element farther to the right, with the suffix -ide added to the name of the latter:
69.Entropy is a measure of how energy becomes disorderly in a system. Disorder increases and entropy increases. How is this related to opening a bottle of perfume in the corner of a room?
The natural state of the perfume molecules is to spread out, a state of higher probability, and a state of increasing entropy. Perfume molecules and their smell will soon drift to all parts of the room.
properties of nonmetals
The nonmetallic elements, with the exception of hydrogen, are on the right side of the periodic table. Nonmetals are very poor conductors of electricity and heat, and may also be transparent. Solid nonmetals are neither malleable nor ductile. Rather, they are brittle and shatter when hammered. At 30°C (86°F), some nonmetals are solid (carbon, C), others are liquid (bromine, Br), and still others are gaseous (helium, He).
27.What is the relationship between the maximum number of electrons each shell can hold and the number of elements in each period of the periodic table?
The number of electrons that each shell can hold corresponds to the number of elements in the period.
61.Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom?
The one on the far right where the nucleus is not visible.
Atomic spectrum
The pattern of frequencies of electromagnetic radiation emitted by the atoms of an element, considered to be an element's "fingerprint."
11.How many periods are there in the periodic table? How many groups?
The periodic table has 7 periods and 18 groups.
55.Use Exercise 53 as an analogy to describe what occurs in Exercise 54. Does it make sense to think that the alcohol is made of very tiny particles (molecules) rather than being an infinitely continuous material?
The popcorn in the skillet can represent the alcohol molecules lying on the surface of the table top. As the kernels are heated they eventually leave the skillet. Likewise, as the alcohol molecules absorb heat from the table top they evaporate away from the table top. Do you see how easy it is to explain the disappearance of the alcohol by supposing the existence of alcohol molecules? We find that the concept of molecules can be used to readily explain so many different phenomena. This is why so many people came to believe in their existence many years before the discovery of direct evidence.
77.In Bohr's planetary model of the atom, what does the principal quantum number represent?
The principal quantum number represents the permitted energy levels of electrons.
42.The atoms that compose your body are mostly empty space, and structures such as the chair you're sitting on are composed of atoms that are also mostly empty space. So why don't you fall through the chair?
The range of the atom's electrical field is much greater than the atom's empty space. When you sit on a chair, the atoms' electrons and your electrons repel each other with such a force that holds you up so you are sitting.
49.If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains?
The remaining nucleus is that of Carbon-12.
75. Stand on a bathroom scale and read your weight. When you lift one foot up so that you're standing on one foot, does the reading change? Does a scale read force or pressure?
The scale measures force, not pressure, and is calibrated to read your weight. That's why your weight on the scale is the same whether you stand on one foot or both.
actinides
The seventh-period inner transition metals are called the _______ because they fall after actinium, Ac.
25.Does the periodic table explain the shell model, or does the shell model explain the periodic table?
The shell model is used to explain the organization of elements within the periodic table. With the shell model, for example, we can understand how the atoms of elements get larger moving down a group or how they get smaller when moving from left to right across a period.
lanthanides
The sixth-period inner transition metals are called the __ because they fall after lanthanum
42.While visiting a foreign country, a foreignspeaking citizen tries to give you verbal directions to a local museum. After multiple attempts, he is unsuccessful. An onlooker sees your frustration and concludes that you are not smart enough to understand simple directions. Another onlooker sympathizes with you because he knows how difficult it is to navigate through an unfamiliar city. Which onlooker is correct?
The sympathizing one because you didn't understand the language. That doesnt make you inherently dumb, just unprepared.
67.Which law of thermodynamics involves absolute zero?
The third law, which states that no system can reach absolute zero.
93. Why is the pressure in an automobile's tires slightly greater after the car has been driven several kilometers?
The tires heat, giving additional motion to the gas molecules within the tires.
subtracting its atomic number from its mass number
The total number of neutrons in an isotope can be calculated by
117.Which teapot holds more liquid?
The water can be no deeper than the spouts, which are at the same height, so both teapots hold the same amount of liquid.-
121.A barge filled with scrap iron is in a canal lock. If the iron is thrown overboard, does the water level at the side of the lock rise, fall, or remain unchanged? Discuss your explanation with your discussion group.
The water level will fall. This is because the iron will displace a greater amount of water while being supported than when submerged. A floating object displaces its weight of water, which is more than its own volume, while a submerged object displaces only its volume. (This may be illustrated in the kitchen sink with a dish floating in a dishpan full of water. Silverware in the dish takes the place of the scrap iron. Note the level of water at the side of the dishpan, and then throw the silverware overboard. The floating dish will float higher and the water level at the side of the dishpan will fall. Will the volume of the silverware displace enough water to bring the level to its starting point? No, not as long as it is denser than water.)
83. When a wooden block is placed in a beaker that is brim full of water, what happens to the scale reading after water has overflowed? Answer the same question for an iron block.
The weight on the scale doesn't change, for the weight of the brim-full beaker is the same whether or not a block floats in it, because the block's weight equals the weight of water that overflows ( Figure 5.16). But not so with an iron block that sinks in the water and is heavier than the water displaced. The reading increases when the iron block is in the beaker.
97. Why is there no atmosphere on the Moon?
There is no atmosphere on the Moon because the speed of a sizable fraction of gas molecules at ordinary temperatures exceeds lunar escape velocity (because of the Moon's smaller gravity). Any appreciable amounts of gas have long ago leaked away, leaving the Moon airless.
95.Why can't you determine whether you are running a fever by touching your own forehead?
There would be no temperature difference between your hand and forehead. If your forehead is a couple of degrees higher in temperature than normal, then your hand is also a couple of degrees higher.
The total energy (kinetic plus potential) of the submicroscopic particles that make up a substance.
Thermal energy
65.If 100 joules of heat is added to a system that does 40 joules of external work, by how much is the thermal energy of the system raised?
Thermal energy of the system is raised by 60 J. (100 J = 60 J + 40 J)
The study of thermal energy and its relationship to heat and work.
Thermodynamics
Which are older: the atoms in the body of an elderly person or those in the body of a baby?
They are of the same age, which is appreciably older than the solar system.
92. In a sporting goods store, you see what appear to be two identical life preservers of the same size. One is filled with Styrofoam and the other one with lead pellets. If you submerge these life preservers in the water, upon which is the buoyant force greater? Upon which is the buoyant force ineffective? Why are your answers different?
They have the same bouyant force because they are the same size and according to Archimede's principle, any body submerged in a fluid is bouyed up by a force equal to weight of luid the body disp[places. The bouyantb force is ineffective on th epreserver full of pellets becuse the rpeserver has more density due to the heavy pellets inside it. This makes it have more mass than the bouyant force cn push and it sinks to tyhe botom.
80.What might the spectrum of an atom look like if the atom's electrons were not restricted to particular energy levels?
They would all show every color possible because they are no longer restricting certain frequencies of energy but rather letting them all in, so they would emit every type of light because they are emitting every type of frequency.
actinide properties
They, too, all have similar properties and hence are not easily purified. Actinides heavier than uranium are not found in nature but are synthesized in the laboratory.
76.How can a hydrogen atom, which has only one electron, create so many spectral lines?
This is because it may only contain one electron, but when it is removed from hydrogen and used for light, it contains a packet of energy called a quantum. This packet of energy contains numerous amounts of energy which gives us the multiple different colors of light because some of the energy will be high frequency while some will be low.
amu
This is the atomic mass unit,
that every particle of matter is somehow endowed with a wave to guide it as it travels. The more slowly an electron moves, the more its behavior is that of a particle with mass. The more quickly it moves, however, the more its behavior is that of a wave of energy.
This question was posed by the French physicist Louis de Broglie (1892-1987) while he was still a graduate student in 1924. His revolutionary answer was
Einstein's famous equation E=mc2,
This question was posed by the French physicist Louis de Broglie (1892-1987) while he was still a graduate student in 1924. His revolutionary answer was that every particle of matter is somehow endowed with a wave to guide it as it travels. The more slowly an electron moves, the more its behavior is that of a particle with mass. The more quickly it moves, however, the more its behavior is that of a wave of energy.This duality is an extension of
Interestingly,_______ is given a direction via this thermodynamic rule.
Time
127.Two teams of eight horses each were unable to pull the Magdeburg hemispheres apart (Figure 5.20). Why? Suppose two teams of nine horses each could pull them apart. Then would one team of nine horses succeed if the other team were replaced with a strong tree? Discuss and defend your answer.
To begin with, the two teams of horses used in the Magdeburg hemispheres demonstration were for showmanship and effect, for a single team and a strong tree would have provided the same force on the hemispheres. So if two teams of nine horses each could pull the hemispheres apart, a single team of nine horses could also, if a tree or some other strong object were used to hold the other end of the rope.
photon
To emphasize their particulate nature, each quantum of light was called a ______, a name coined because of its similarity to the words electron, proton, and neutron.
75.What is the chemical name for a compound with the formula Ba3N2?
Tribarium dinitride, or more simply, barium nitride because no ratio other than three bariums to two nitrogens is possible.
123.If you wish to save fuel and you're going to leave your warm house for half an hour or so on a very cold day, should you turn your thermostat down a few degrees, turn it off altogether, or let it remain at your preferred room temperature? This question should elicit much discussion!
Turn your heater off altogether to save fuel. When it is cold outside, your house is constantly losing heat. How much is lost depends on the insulation and the inside and outside temperature differences (Newton's law of cooling). Keeping ΔT high consumes more fuel. To consume less fuel, keep ΔT low and turn your heater off altogether. Will more fuel be required to reheat the house when you return than would have been required to keep it warm while you were away? Not at all. When you return, you are replacing heat lost by the house at an average temperature below the normal setting, but if you had left the heater on, it would have supplied more heat, enough to make up for heat lost by the house at its normal, higher temperature setting. (Perhaps your instructor will demonstrate this with the analogy of leaking water buckets.)
98. We can understand how pressure in water depends on depth by considering a stack of bricks. The pressure below the bottom brick is determined by the weight of the entire stack. Halfway up the stack, the pressure is half, because the weight of the bricks above is half. To explain atmospheric pressure, we should consider compressible bricks, like foam rubber. Why is this so?
Unlike water, air is comrpeessible, so when air stacks on top of itself, it compresses the deeper you go, which is why air oressure is much greater than that of air pressure high up in the air
Niels Bohr
Using Planck's quantum hypothesis, the Danish scientist _______ (1885-1962) explained the formation of atomic spectra
85.What does the planet Venus have to do with Earth's greenhouse effect?
Venus is thought to have been Earthlike in the past, with a tipping point of carbon dioxide buildup that makes it now uninhabitable, which serves as a warning for Earth.
_______ has a much higher capacity for storing thermal energy than almost any other substance.
Water
129.Why does spraying fruit trees with water before a frost help protect the fruit from freezing?
Water can emit a lot of heat. Aborsbs heat. Good absorber is a good emitter, and also the fact that the coating of ice acts as an insulating blanket. Every gram of water that freezes releases 80 calories, much of it to the fruit; the thin layer of ice then acts as an insulating blanket against further loss of heat.
128.Why does placing a tub of water in a farmer's canning cellar help prevent canned food from freezing in cold winters?
Water can emit a lot of heat. Aborsbs heat. Good absorber is a good emitter.
75.Why does jello stay cooler for a longer time than sandwiches when both are removed from a picnic cooler on a hot day?
Water in the jello has more "thermal inertia"—a higher specific heat capacity than sandwich ingredients. Be glad water has a high specific heat capacity the next time you're enjoying cool jello on a hot day.
91.State an exception to the claim that all substances expand when heated.
Water is an exception. Between 4° C and 0°C, water expands when cooled.
118.Suppose you wish to lay a level foundation for a home on hilly and bushy terrain. How can you use a garden hose filled with water to determine equal elevations for distant points?
Water seeks its own level from pressure. This means the heitght of water will be the same throughout. This mea s that when you law out the hose on th eground and therr eis a deeo spot, you will nptice the height of the water in the hose is lower. The same applies for a bump. If it goes oevr the bump, you will notice that there is no water on one side of the hose.
71.Why isn't water classified as an element?
Water use to be classified as an element but that was before people recognized that the basic building block of matter are these tiny particles called atoms. Today, an element is identified as a material consisting only one kind of atom.
If the voltage is expressed in volts and the current in amperes, then the power is expressed in watts. So, in units form,
Watts=amperes×volts
68.With scanning probe microscopy technology, we see not actual atoms, but rather images of them. Explain.
We don't know exactly what the atoms look like. A scanning probe microscope uses a needle that drags across the bumpy surface of an object, which would be the atoms. We don't see the atoms, we just see what is felt by the needle as it travels across multiple atoms.
total number of protons and neutrons
We identify isotopes by their mass number, which is the
alkali propoerties
We now know that alkaline ashes contain compounds of group 1 elements, most notably potassium carbonate, also known as potash.
129.If you bring an airtight bag of potato chips aboard an airplane, you'll note that it puffs up as the plane ascends to high altitude. Why?
Whatever air is inside when on the ground expands against the decreased cabin pressure when the plane is aloft. Air pressure in the bag is then greater than the surrounding atmospheric pressure.
79.How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?
When a wave is confined, it is reinforced only at particular frequencies. The electron wave being confined to the atom, therefore, only exhibits particular frequencies where each frequency represents a discrete energy value.
How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?
When an electron wave is confined, it is reinforced only at particular frequencies.
76. Why are people who are confined to bed less likely to develop bedsores on their bodies if they use a waterbed rather than a standard mattress?
When laying on a mattress, it is solid and only applies force upwards. When you lay on it, only parts of yur body are actaully tpuching it. This applies more pressure to those parts of your body, while some have less or no pressure applied to them at all. This causes bedsores. Waterbeds, on th eother hand, have you sink into them and pressure in a fluid at any point is exerted equally in all directions, so every part if your body is being pushed on by pressure.
85. Why does a volleyball that is held beneath the surface of water have more buoyant force than a volleyball that is floating?
When the ball is held beneath the surface, it displaces a greater weight of water.
87.For many years, a method for breaking boulders was putting them in a hot fire and then dousing them with cold water. Why would the boulders fracture?
When the boulders are doused, the outer part of the boulders cools while the insides are still hot. This causes a difference in contraction, which fractures the boulders.
125.When an ice cube in a glass of water melts, does the water level in the glass rise, fall, or remain unchanged? Does your answer change if the ice cube contains many air bubbles? Discuss whether or not your answer changes if the ice cube contains many grains of heavy sand.
When the ice cube melts the water level at the side of the glass is unchanged (neglecting temperature effects). To see this, suppose the ice cube is a 5-gram cube; then while floating it will displace 5 grams of water. But when melted it becomes the same 5 grams of water. Hence the water level is unchanged. The same occurs when the ice cube with the air bubbles melts. Whether the ice cube is hollow or solid, it will displace as much water floating as it will when melted. If the ice cube contains grains of heavy sand, however, upon melting, the water level at the edge of the glass will drop. This is similar to the case of the scrap iron of Question 116.
125.Place a jar of water on a small stand on the bottom of a saucepan of water. Then the bottom of the jar is positioned above the bottom of the pan. When the pan is put on a stove, the water in the pan boils, but the water in the jar does not. Why?
When the saucepan and jar both reach the boiling temperature, further heat does not enter the jar because it is in thermal equilibrium with the surrounding 100°C water in the saucepan. This is the principle of the "double boiler."
Guideline 2
When two or more compounds have different numbers of the same elements, prefixes are added to remove the ambiguity. The first four prefixes are mono- (one), di- (two), tri- (three), and tetra- (four). The prefix mono-, however, is commonly omitted from the beginning of the first word of the name:
72.If you eat metallic sodium or inhale chlorine gas, you stand a strong chance of dying. Let these two elements react with each other, however, and you can safely sprinkle the compound on your popcorn for better taste. What is going on?
When you combine these two elements into a compound, their toxic properties go away. A compound's atoms can act totally differently than how they act on their own.
inner transition metals.
Within the sixth period is a subset of 14 metallic elements (atomic numbers 58 to 71) that are quite unlike any of the other transition metals. A similar subset (atomic numbers 90 to 103) is found within the seventh period. These two subsets are the
126.A piece of metal and an equal mass of wood are both removed from a hot oven at equal temperatures and dropped onto blocks of ice. The wood has a higher specific heat capacity than the metal. Which melts more ice before cooling to 0°C?
Wood: has higher specifc heat
64.Wood has a very low conductivity. Does it still have a low conductivity if it is very hot that is, in the stage of smoldering red hot coals? Could you safely walk across a bed of red hot wooden coals with bare feet? Although the coals are hot, does much heat conduct from them to your feet if you step quickly? Could you do the same on pieces of red hot iron? Explain. (CAUTION: Coals can stick to your feet, so OUCHdon't try this!)
Yes because when something is a good insulator, it is a good absorber as well and in this case, it absorbs plenty of heat to make it very hot. You could safely walk barefoot across a bed of hot coals because they are good insulators so they will not transfer much heat to your feet. If you were to step quickly across these coals, you will burn yourself because your feet will make thermal energy which will heat them up and in turn begin absorbing more energy to keep yourself moving. Iron is a very good conductor
45.Is the head of a politician really 99.99999999% empty space?
Yes, as is everyone else's and everything around you. We interact with our environment, like bumping our head against a cabinet, because of the repulsive electric fields that prevent atoms from overlapping one another.45- everything will be that the reason we don't look see through is because we reflect light
58.With no one looking, you add 5 mL of a cinnamon solution to a blue balloon, which you tie shut. You also add 5 mL of fresh water to a red balloon, which you also tie shut. You heat the two balloons in a microwave until each inflates to about the size of a grapefruit. Your brother then comes along, examines the inflated balloons, and tells you that the blue balloon is the one containing the cinnamon. How did he know?
You can smell IT. Hotter=Evaporate. More particles in air= stronger smell
107.When can you withdraw heat from a substance without lowering its temperature? Give an example.
You can withdraw heat without lowering temperature when the substance is undergoing a change of phase. Small amounts of heat taken from 0°C water, or from 100°C steam, for example, doesn't lower temperature.
97.Room temperature water boils spontaneously in a vacuum on the Moon, for example. Could you cook an egg in this boiling water? Explain-
You could not cook food in low-temperature water that is boiling by virtue of reduced pressure. Food is cooked by the high temperature that food is subjected to, not by the bubbling of the surrounding water. For example, put room-temperature water in a vacuum and it will boil. But this doesn't mean the water will transfer more thermal energy to an egg than before boiling—an egg in this boiling water won't cook at all!
83.The British diplomat, physicist, and environmentalist John Ashton, in speaking to a group of scientists, stated (paraphrased): "There has to be much better communication between the world of science and the world of politics. Consider the different meanings of the word uncertainty. To scientists, it means uncertainty over the strength of a signal. To politicians it means 'go away and come back when you're certain.' " Pretend you are a scientist with strong but inconclusive evidence in support of impending climate change. How might you best persuade politicians to take action?
You probably should not spend too much time of showing the politicians your analysis of the data. If your credentials are good and you are respected among your peers, then the politicians will likely trust your assessments. Politicians will be much more interested in the impact such climate change will have on the general public, especially in terms of the economy. Your time would be well spent focusing on potential solutions to the problem. All the better if your solutions offered new jobs for the politician's constituents. John Ashton also said, "The more effort scientists put into how their message might be heard, how it might be manipulated and made mischief, the better. If we want to successfully respond to climate change we have to form it as part of the solution to the economic crisis."
86.Alcohol evaporates more rapidly than water at the same temperature. Which produces more cooling: alcohol or the same amount of water on your skin?
Your hand gives alcohol more energy to evaporate at this faster rater, thus your hand is cooler when alcohol evaporates off your hand compared to water
Any path along which electrons can flow is
a circuit
For a continuous flow of electrons, there must be
a complete circuit with no gap
rust is
a compound consisting of iron and oxygen atoms.
Conversion from ac to dc is accomplished with an electronic device that allows electron flow in one direction only
a diode
Lift is greater when there is
a large wing area and when the plane is traveling fast.
The periodic table is
a listing of all the known elements with their atomic masses, atomic numbers, and atomic symbols.
The significance of voltage is that a definite value for it can be assigned to
a location
4.How many types of atoms can you expect to find in a pure sample of any element?
a lot
A high voltage means
a lot of energy only if a lot of charge is involved
When liquid presses against a surface
a net force is directed perpendicular to the surface
First, in a physical change, a change in appearance is the result of
a new set of conditions imposed on the same material. Restoring the original conditions restores the original appearance: frozen water melts upon warming.
Temperature is
a per-particle property
65.Classify each change as physical or chemical. Even if you are incorrect in your assessment, you should be able to defend why you chose as you did. Grass grows. An infant gains 10 lb. A rock is crushed to powder.A tire is inflated with air.
a) chemical. b) chemical. c) physical. d) physical.
100.Why does putting a lid over a pot of water on a stove shorten the time needed for the water to come to a boil, whereas after the water boils, the use of the lid only slightly shortens the cooking time?
add thermal energy to bottom, lose at the top. When a lid is on, it keeps more thermal energy from escaping. Temperature doesn't change when boiling happens.
An object that has equal numbers of electrons and protons has no net electric charge. But if the numbers do not balance, the object is then electrically charged. An imbalance comes about by
adding or removing electrons.
122.Suppose that at a restaurant, you are served coffee before you are ready to drink it. In order that it be as hot as possible when you are ready for it, would you be wiser to add cream to it right away or to add cream just before you are ready to drink it? This question should elicit much discussion!
adding the creamer right awayu because it makes stghe cofee whiter which makes it a worse emitter because black is a good emitter and whit is less. and get to desired temp fast
stardust, as is everything that surrounds you.
all the atoms that occur naturally on Earth including those in your body are the products of stars. You are made of
The spectroscope
allows us to analyze the light emitted by elements as they are made to glow.
70.What do the components of a conceptual model have in common?
almost never represnts an actual dpeictuon of one but rather explains how it works
The rate of electrical flow is measured in
amperes
An aneroid barometer calibrated for altitude is called
an altimeter (altitude meter)
You say that charges flow through a circuit because of
an applied voltage across the circuit
Every bit of matter, wires included, contains enormous numbers of electrons that swarm about in random directions. When a source of voltage sets them moving, we have
an electric current.
just any amount of potential energy.
an electron cannot have
is farther from the nucleus
an electron has more potential energy when it
As we shall see in the next two sections, iron is
an element,
Generally, element is used in reference to
an entire macroscopic or microscopic sample,
The top down approach is
an extension of microtechnology techniques to smaller and smaller scales
A small portable instrument that measures atmospheric pressure is
aneroid barometer
What they all have in common is that air is made to flow faster over the wing's top surface than under its lower surface. This is mainly accomplished by a tilt in the wing, called its
angle of attack
all neutrons
are identical.
Nonmetals
are very poor conductors of electricity and heat, and may also be transparent.
106.When can you add heat to a substance without raising its temperature? Give an example.
as it melts, it doesn't go up. As it boils is doesn't go up.
8.Distinguish between atomic number and mass number.
atomic amss is average mass of all an element's isotopes and mass number is the amount of neutrons and protons in an isotope
All three of these transformations involve a change in the way the
atoms in the molecules are chemically bonded to one another
Light is given off by
atoms subjected to various forms of energy, such as heat or electricity.
If instead you rub a glass test tube with silk and bring the rubbed glass near the hanging straw, the two rubbed ends
attract.
54.Why are the atomic masses listed in the periodic table not whole numbers?
average atomic mass is average mas of random element and all it's isotopes few would differentiate so different mass
Temperature is proportional to the
average translational kinetic energy per particle that makes up a substance
90.Porous canvas bags filled with water are used by travelers in hot weather. When the bags are slung on the outside of a fast moving car, the water inside the bags is cooled considerably. Explain.-
bag allows it to be wet which causes water outside to be evaporated and cooled
You could swallow a capsule of germanium, Ge (atomic number 32), without significant ill effects. If a proton were added to each germanium nucleus, however, you would not want to swallow the capsule, because the germanium would
become arsenic.
The fact that different substances expand at different rates is nicely illus-trated with a
bimetallic strip
Copper has the chemical property of reacting with carbon dioxide and water to form a greenish
blue solid known as -patina.
Six elements are classified as metalloids:
boron, B; silicon, Si; germanium, Ge; arsenic, As; antimony, Sb; and tellurium, Te.
80.How is chemistry similar to nanotechnology? How is it different?
both have to do with molevules andatoms. Chemistry is a gorup of atoms. nanotechnology is individual atoms
108.What does an air conditioner have in common with a refrigerator?
both suck out thermal energy from stuff
For a gas, we refer to how fast the gas particles are
bouncing back and forth
These devices are commonly connected in a circuit in one of two ways: in series or in parallel. When connected in series, they form a single pathway for electron flow between the terminals of the battery, generator, or wall outlet (which is simply an extension of these terminals). When connected in parallel, they form
branches, each of which is a separate path for the flow of electrons.
72.After a car is driven along a road for some distance, why does the air pressure in the tires increase?
build up in fricion
The bottom up approach involves
building nanosized objects atom by atom
88.Astronomical measurements reveal that about 90% of the mass of the universe is invisible to us. This invisible matter, also known as dark matter, is likely to be "exotic" matter—very different from the elements that make up the periodic table (see Section 28.4). We know the dark matter is there because of its gravitational effects, but scientists can only guess as to its nature. What do you think dark matter might be made of? How soon might we know the answer?
can't see atoms so we use information gatehred to determin an answer
The methane of natural gas has the chemical property of reacting with oxygen to produce
carbon dioxide and water, along with appreciable heat energy
66.With the periodic table as your guide, describe the element selenium, Se (atomic number 34), using as many of this chapter's key terms as you can.
chalcogen. prob found in ores. 16 valance eletrons. gas at room temperature. likely to form ionic bonds. 45 neutronns in most cases.
You don't say that voltage flows through a circuit. Voltage doesn't go anywhere, for it is the
charges that move. Voltage produces current (if there is a complete circuit).
Thus, the term chemical change means the same thing as
chemical reaction
82.Your friend smells cinnamon coming from an inflated rubber balloon containing cinnamon extract. You tell him that the cinnamon molecules are passing through the micropores of the balloon. He accepts the idea that the balloon contains micropores but insists that he is simply smelling cinnamonflavored air. You explain that scientists have discovered that gases are made of molecules, but that's not good enough for him. He needs to see the evidence for himself. How might you lead him to accept the concept of molecules?
cinamon and air molcules can escape. not cinampn flavoed ir but rather air cotaing both while scaping
Absolute zero isn't the coldest you can get. It's the
colest you can hope to apporach
This results in ice water being less dense than slightly warmer water. As the temperature of water is increased from 0°C, more of the ice crystals
collapse
Compounds have physical and chemical properties that are
completely different from the properties of their elemental components.
124.If you wish to save fuel and you're going to leave your cool house for half an hour or so on a very hot day, should you turn your air
conditioning thermostat up a bit, turn it off altogether, or let it remain at your preferred room temperature? This question should elicit much discussion!-Turn off. Heat raises to baseline temp. Not much replacement. No constantr enegry add needed
Electrical devices connected to the same two points of an electrical circuit are said to be
connected in parallel.
68.Octane is a component of gasoline. It reacts with oxygen, O2, to form carbon dioxide and water. Is octane an element or a compound? How can you tell?
coumpound becayse Water and cabron Dioxide have Hydrogen and carbon, something taht oxygen does not posess, so out of order of deduction, Octance has CArbon and Hydrogen making it a compound
63.Visit a snow
covered cemetery and note that the snow does not slope upward against the gravestones but, instead, forms depressions around them, as shown. What is your explanation for this?-Heat from the relatively warm ground is conducted by the gravestone to melt the snow in contact with the gravestone. Likewise for trees or any materials that are better conductors of heat than snow, and that extend into the ground.
The damaging effects of shock are the result of
current passing through the human body.
The greater the voltage, the greater the
current.
table chart showed
densities of materials, etc
A wholly new approach involves
designing logic boards in which molecules (not electric circuits) read, process, and write information. One molecule that has proved most promising for such molecular computation is DNA, the same molecule that holds our genetic code
112.When a steadily flowing gas flows from a larger
diameter pipe to a smaller-diameter pipe, what happens to (a) its speed, (b) its pressure, and (c) the spacing between its streamlines?-112. The speed increases, the pressure decreases, and the streamlines get closer. This is because of Bernoulli's Principle which states that when speed in a fluid increases, internal pressure in it decreases. Secondly, streamlines are the motion of fluid. This all means that when the fluid goes into a narrower path, the lines will have to get closer together to all fit in it, and this means that they begin to add onto each other which increases speed, and form what we have just gathered, as the speed of a fluid increases, it's internal pressure decreases.
74.How might you distinguish a sodium-vapor streetlight from a mercury-vapor streetlight?
dif colors
To attain a sustained flow of charge in a conductor, some arrangement must be provided to maintain a
difference in potential while charge flows from one end to the other.
Equal masses of different materials require_________ to change their temperatures by a specified number of degrees.*
different quantities of heat
How much energy is required to tear an electron away from an atom varies for
different substances.
Electric current may be
direct or alternating
Although the innermost electrons in an atom are held very tightly to the oppositely charged atomic nucleus, the outermost electrons of many atoms are held very loosely and can be easily
dislodged.
The addition of heat causes these vibrations to increase until, at a certain temperature, the vibrations are rapid enough to
disrupt the fixed arrangements. Rock melts into magma (a topic of much discussion in Part 3). Likewise, ice melts into water.
Any object that is electrically charged has an excess or deficiency of some whole number of electrons electrons cannot be
divided into fractions of electrons.
electron
dot structure,- used to show how atoms join together to form molecules, which are tightly held groups of atoms
lanthanide properties
due to their similariteis with lanthanum, they tend to occur mixed together in the same locations on Earth. Also because of their similarities, lanthanides are unusually difficult to purify.
Electrons and protons have
electric charge
Rubbing two materials together transfers "__________" from one material to the other.
electric fluid
Franklin couldn't see which fluid was transferred when the glass was rubbed with silk. He decided to call the glass positively charged, which means that the silk ended up with a negative charge because it lost
electric fluid to the glass.
Electric potential energy differs from
electric potential (or voltage).
In order for you to receive a shock, there must be a difference in
electric potential between one part of your body and another part.
Twice the charge in the same location has twice the
electric potential energy
In chemical batteries, this work may be done by the chemical disintegration of zinc or lead in acid, and the energy stored in the chemical bonds is converted to
electric potential energy.
opper has a low
electrical resistance,
Generators separate charge by
electromagnetic induction, a process we will describe in the next
26.Which electrons are most responsible for the properties of an atom?
electrons
The nucleus attracts the electrons and holds them in orbit, similar to the way the Sun holds the planets in orbit. But with a difference electrons repel other
electrons (whereas gravitational forces only attract).
The fundamental unit of an element is indicated by its
elemental formula
64.Helium, He, is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table. Why?
elements are placed due to their characteristics. Hydrogen is similar to alkaline metals. Helium is similar to noble gases. The reason for this huge dif is Helium has a full valence shell while hydrogen doesn't
chalcogens ("oreforming" in Greek)
elements of group 16 are known as the ________ because the top two elements of this group, oxygen and sulfur, are so commonly found in ores.
116.What is the source of energy that keeps the dunking bird in Figure 7.28 operating?
energy in the room keeps it moving. Hotter= work better. water is eveaporating of ht head. This makes ether inside condense. This decreases prressure which makes fluid go up the tube
when an atom absorbs a photon of light, it is absorbing
energy. This energy is acquired by one of the electrons. Because this electron has gained energy, it must move away from the nucleus.
liquid pressure is exerted ________- in alll directuons
equally
With increases in temperature, liquids _______ more than solids.
expand
Most substances _______ when heated and _________ when cooled.
expand contract
Notice also that many bridges have tongue-and-groove gaps called
expansion joints
20.Which has more potential energy: an electron close to an atomic nucleus or one far from an atomic nucleus?
far
an electron has more potential energy when it is
farther from the nucleus
24.How does the speed of an electron change its fundamental nature?
faster becomes like a wave and either reinforces it's area or if better, goes to new energy level and reinforces it
86.Use the shell model to explain why a lithium atom, Li, is larger than a beryllium atom, Be.
fewer electrons. less force pull
62.Wood is a better insulator than glass. Yet fiberglass is commonly used as an insulator in wooden buildings. Explain.
fiber glass is 95% air which makes it a good insulator.
Three lamps are connected in series with a battery. The same current exists almost immediately in all three lamps when the switch is closed. The current does not "pile up" or accumulate in any lamp but instead
flows through each lamp
-Pressure Formula
force/area
Halogen properties
form salts
FareneheitOn this scale the number 32 is assigned to the temperature at which water
freezes
When you place a warm object and a cool object in close proximity, thermal energy transfers in a direction
from the warmer object to the cooler object
Electrical forces, like gravitational forces, can act between things that are not in contact with each other. For both electricity and gravity, a force field exists that influences distant charges and masses, respectively. The properties of space surrounding any mass are altered such that another mass introduced to this region experiences a force. This "alteration in space" is called its
gravitational field.
Volume decreases as ice crystals collapse, while volume increases due to
greater molecular motion
But if the resistance is doubled for a circuit, the current is
half what it would have been otherwise.
105.What role does antifreeze play in preventing the freezing of water?
has a lower freezing point than water, so it mixes with it and prevents it from freezing at it's normal 32 degrees
[one cycle per second is called a
hertz (Hz)]
photons are emitted by atoms as electrons move from
higher-energy outer orbits to lower-energy inner orbits.
59.Instead of saying a red
hot horseshoe contains heat, it is correct to say a red-hot horseshoe contains what?-thermal energy
one in which the disturbing effects of the forces between molecules and the finite size of the individual molecules can be neglected.
ideal gas
How can you determine whether an observed change is physical or chemical? This can be tricky because
in both cases, changes in physical appearance occur.
68.When air is rapidly compressed, why does its temperature increase?
increasing temperature expand the air but if you stop increase the temperature, the air will start to compress again
14.When we use a scanning probe microscope, do we see atoms directly or do we see them only indirectly?
indirectly
Electric potential and voltage are the same thing, and they are commonly used
interchangeably.
The circuit shown in Figure 8.31 illustrates the following major characteristics of parallel connections:Current through the voltage source divides among the parallel branches. Because the voltage across each branch is the same, the amount of current in each branch is
inversely proportional to the resistance of the branch.
A charged atom is called an
ion
The rusting of a car, by contrast, is the result of the transformation of iron to rust. This is a chemical change because
iron and rust are two different materials, each consisting of a different arrangement of atoms.
all wings have one thing in common
is that air is made to flow faster over the wing's top surface than under its lower surface.
The carat
is the common unit used to describe the mass of a gem
The karat
is the common unit used to describe the purity of a precious metal, such as gold.
At the microscopic level, physical structure is so fine that
it can be seen only with a microscope.
Chemistry is often described as a central science because
it touches all the other sciences.
18.Why do we say atomic spectra are like fingerprints of the elements?
its the distinct pattern of frequencies emmitetd by an atom
Heat, like work, is energy in transit and is measured in
joules or calories
132.Your study partner says he doesn't believe in Bernoulli's principle and cites as evidence the fact that a stream of water can knock over a building. The pressure that the water exerts on the building is not reduced, as Bernoulli claims. What distinction is your partner missing?
k
76.When a 1
kg metal pan containing 1 kg of cold water is removed from the refrigerator and set on a table, which absorbs more heat from the room—the pan or the water?-76. The water does because it has a much greater specific heat capacity than the pan. Because that is the case, according to Newton's 2nd Law, heat never goes from cold to hot in nature and everything goes from a high quality energy or a lower quality energy and everything goes from order to disorder. This means that since the water will have a much bigger capacity for heat, it will have a lower temperature, so the heat of the pan will transfer to the water as well as heat generally being absorbed by the water,
A common heat unit for labeling food is the
kilocalorie
If the particle is released, it accelerates in a direction away from the sphere, and its electric potential energy changes to
kinetic energy.
74. Which is more likely to hurt—being stepped on by a 200
lb man wearing loafers or being stepped on by a 100-lb woman wearing high heels?-74. It is more likely to hurt being stepped on a 100 lb woman wearing high heels than a 200 lb man wearing loafers. This is because of pressure. Pressure is the amount of force on a unit of area or the amount of force exerted on a certain amount of area. The formula for this is force divided by area. This means that the bigger the force, the bigger the pressure, and the bigger the area, the less amount of force. In this case, the man would exert more force on you with a force of 2,000 N, but his loafer has a lot more area, so that force is reduced a lot. This can be backed up by Pascal's principle when it states how if a change in pressure happens to a portion of an enclosed fluid at rest, it equally affects the entire fluid. This means that if you were you exert a ;large force over a small pressure plate that transmits to a large piston to push it up, the force would affect the large large with just as much exerted on the small pressure plate, but the pressure would be less because the force would have to split up to cover the entire piston, thereby making the force the same, but the pressure less. Back on the subject of the man's shoe, when he exerts that force, the force must split upt to cover the shoe's larger area, which will make the actual pressure on you less. Meanwhile, the 100lb lady has only a force of 1,000 N exerted on you, but she would have a larger pressure because her high heels have less area, which means the force doesn't have to split up as much to cover the whole area. This will mean that the pressure of the 1,000 N will be lowered only a little bit compared to the pressure of the 2,000 N loafers.
Most of the current passes along the path of
least electrical resistance connecting these two points.
Three lamps are connected in series with a battery. The same current exists almost immediately in all three lamps when the switch is closed. The current does not "pile up" or accumulate in any lamp but flows through each lamp. Electrons that make up this current do what?
leave the negative terminal of the battery, pass through each of the resistive filaments in the lamps in turn, and then return to the positive terminal of the battery.
ice is ____ ______than water
less dense
The circuit shown in Figure 8.31 illustrates the following major characteristics of parallel connections:As the number of parallel branches is increased, the overall resistance of the circuit is decreased. Overall resistance is lowered with each added path between any two points of the circuit. This means the overall resistance of the circuit is
less than the resistance of any one of the branches.
When the average pressure difference over the wing is multiplied by the surface area of the wing, we have a net upward forc
lift
Electricity is usually fed into a home by way of two wires called
lines
As thermal motion increases, a solid object first melts and becomes a _______. With more thermal motion it then ________. As the temperature further increases, molecules break apart (dissociate) into atoms, and atoms lose some or all of their electrons, thereby forming a cloud of electrically charged particles—a _______.
liquid vaporizes plasma
3 metals less dense than watewr
lithium, sodium, pottatsium
The more transistors they could squeeze into a circuit, the more powerful the
logic board
110.The force of the atmosphere at sea level against the outside of a 10
m2 store window is about 1 million N. Why does this not shatter the window? Why might the window shatter in a strong wind blowing past the window?- Two different presures are pushing on the window formdifferent sides which balances things out. Shatters if a strong wind blows because that means it will have smaller pressure and therefore the otehr pressure will overpower it on the otehr side and break the window. BERNOULLI PRINCLE
10.Are most elements metallic or nonmetallic?
metallic
transition metal prioperteis
metals that do not form alkaline solutions with water. These metals tend to be harder than the alkali metals and less reactive with water; hence they are used for structural purposes.
when a high potential energy electron in an atom loses some of its energy, the electron
moves closer to the nucleus and the energy lost from the electron is emitted from the atom as a photon of light. B
The ultimate expert on nanotechnology is
nature.
52.Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation.
neautrons have no electric charge so theya re harder to detect
a positively charged nucleus is surrounded by
negatively charged electrons
Every atom has a positively charged nucleus surrounded by
negatively charged electrons.
If an object gains electric fluid, it becomes positively charged with electric fluid. Likewise, if an object loses electric fluid, it becomes
negatively charged with electric fluid.
A neutral atom has as many electrons as protons, so it has no
net charge
If an electron is removed from an atom, the atom is no longer
neutral.
Without a potential difference,
no flow of charge occurs.
3.What is at the center of every atom?
nucleeus
Processes in which disorder returns to order without external help don't ___________.
occur in nature
Electrical resistance is measured in units called
ohms
How many electrons are there in the third shell of sodium, Na (atomic number 11)?
one
Work can also be done when
one gas expands into another.
Charge is like a baton in a relay race. It can be passed from
one object to another but it cannot be lost.
A positive ion has a net positive charge because it has lost
one or more electrons.
A negative ion has a net negative charge because it has gained
one or more extra electrons.
Time's arrow always points from _________.*
order to disorder
alkaline earth metal properties
orm alkaline solutions when mixed with water. Furthermore, medieval alchemists noted that certain minerals (which we now know are made up of group 2 elements) do not melt or change when put in fire. These fireresistant substances were known to the alchemists as "earth."
Circuits that carry more than a safe amount of current are said to be
overloaded
48.Name ten elements you have access to macroscopic samples of as a consumer here on Earth.
oxygen, iron, copper, lead, nickel, gold, zinc, sliver, chlorine, sodium.
76.What is the common name for dioxygen oxide?
ozone
Because an electron is restricted to discrete orbits, only
particular light frequencies are emitted, as atomic spectra show.
The freezing of water is a _______ because liquid water and frozen water are both forms of water—only the orientation of the water molecules to one another changes.
physical change
what did Otto do
placed together two copper hemispheres about 0.5 m in diameter to form a sphere, as shown in Figure 5.20. He set a gasket made of a ring of leather soaked in oil and wax between them to make an airtight joint. When he evacuated the sphere with his vacuum pump, two teams of eight horses each were unable to pull the hemispheres apart.
All protons are
positively charged and identical;
Under ordinary conditions, there are as many conduction electrons in the atomic lattice as there are
positively charged atomic nuclei.
An object that has unequal numbers of electrons and protons is electrically charged. If it has more electrons than protons, the object is negatively charged. If it has fewer electrons than protons, then it is
positively charged.
Similarly, a charged object has
potential energy by virtue of its location in an electric field.
coffee and tea are decaffeinated using carbon dioxide in a fourth phase of matter known as a supercritical fluid. This phase behaves like a gaseous liquid, which is attained by adding lots of
pressure and heat.
The nucleus is composed of
protons and neutrons. (The common form of hydrogen, which has no neutrons, is the only exception.)
The second law speaks of the
quality of energy,
The first law of thermodynamics states that energy can be neither created nor destroyed. It speaks of the
quantity of energy
In the language of chemistry, materials undergoing a chemical change are said to be
reacting.
Most circuits have more than one device that
receives electric energy
self
reinforcing-The only waves that an electron exhibits while confined to an atom are those that are
while a strip of rubber has an enormous
resistance.
124.Greta Novak is treated to remarkable flotation in the very
salty Dead Sea. How does buoyant force on her compare when she is floating in fresh water? In answering this question, discuss differences between the volumes of water displaced in the two cases.-124. The salt water has a greater buoyant force because it has a higher density than the fresh water one. This is because of Archimedes Principle which states that a body is buoyed up by a force equal to the weight of the furious displaced by the body. This means that while they both displace the same amount of fluid, the weights of the fluids differ. This means that the high salt water creates a higher density in the water and therefore gives it a bigger weight, so you rise a lot more compared to that of the freshwater and it's low density.
All electrons are identical; that is, each has the
same mass and the same quantity of negative charge as every other electron.
Electric potential and potential mean the
same thing
52.Consider two glasses, one filled with water and the other half full, both at the same temperature. In which glass are the water molecules moving faster? In which is there greater thermal energy? In which will more heat be required to increase the temperature by 1°C?
same. same. full
In every event, whether large
scale or at the atomic and nuclear level, the principle of conservation of charge applies. No case of the creation or destruction of net electric charge has ever been found. The conservation of charge is a cornerstone in physics, ranking with -the conservation of energy and momentum.
At the macroscopic level, matter is large enough to be
seen, measured, and handled
Some materials, such as germanium or silicon, can be made with either an excess or a deficiency of conducting electrons by adding impurities to them. These are
semiconductors.
arrangements of electrons in its atoms, especially the outer
shell electrons. - the properties of an element depend on the
This greatly reduces the resistance in the circuit and is called a
short circuit
for a liquid, we refer to how fast they
slide and jiggle past each otehr
he current inside these and all other electrical devices is regulated by circuit elements called resistors (Figure 8.25), whose resistance may be a few ohms or millions of ohms. Resistors heat up when current flows through them, but for small currents the heating is
slight.
60.Between the act of standing barefoot on top of an igloo and being inside, when does snow act as a conductor and when does it act as an insulator?
snow has air in it and air is a poor conductor which makes snow a good insulator and a poor conductor. snow is a good conductor when you are touching it and not a good one when you are not touching it
113.What physics principle underlies the following three observations? When passing an oncoming truck on the highway, your car tends to sway toward the truck. The canvas roof of a convertible automobile bulges upward when the car is traveling at high speeds. The windows of older passenger trains sometimes break when a high
speed train passes by on the next track.-All are Bernoulli's principle. For the moving car the pressure will be less on the side of the car where the air is moving fastest—the side nearest the truck, resulting in the car being pushed by the atmosphere towards the truck. Inside the convertible, atmospheric pressure is greater than outside, and the canvas rooftop is pushed upwards toward the region of lesser pressure. Similarly for the train windows, where the interior air is at rest relative to the window and the air outside is in motion. Air pressure against the interior surface of the window is greater than the atmospheric pressure outside. When the difference in pressures is large enough, the window is blown out.
16.What does a spectroscope do to the light coming from an atom?
splits it up into all it's different energy levels
Force per unit charge. The electric field can be considered an energetic "aura" surrounding charged objects. About a charged point, the field decreases with distance according to the inverse
square law, like a gravitational field. Between oppositely charged parallel plates, the electric field is uniform.-Electric field
Applying pressure to a gas does what
squeezes the gas particles closer together, which decreases the volume.
65.What is the purpose of the copper or aluminum layer on the bottom of a stainless
steel pot?- Copper and aluminum are better conductors than stainless steel, and therefore transfers heat more quickly to the pot's interior.
An electric field is nature's
storehouse of electric energy.
In solid matter, such as rock, the attractions between particles are
strong enough to hold all the particles together in some fixed three-dimensional arrangement.
The resistance of some materials reaches zero at very low temperatures. These materials are referred to as
superconductors.
coffee and tea are decaffeinated using carbon dioxide in a fourth phase of matter known as a
supercritical fluid.
According to this definition, matter contains
tehrmal energy not heat
Electrons move from the repelling negative terminal toward __________, and they always move________.
the attracting positive terminal; through the circuit in the same directio
mathematical.
the best models of the atom are purely
The unit of charge is called
the coulomb, abbreviated C. It turns out that a charge of 1 C is the charge associated with 6.25 billion billion electrons.
The energy of an emitted photon is equal to
the difference in energy between the two orbits.
The electric signal, however, travels at nearly the speed of light. That's the speed at which
the electric field in the wire is established.
When working with electricity, rather than dealing with the total potential energy of a charged body, it is convenient to consider
the electric potential energy per charge.
In fluids, however, positive ions as well as electrons may constitute
the flow of an electric charge.
Second, in a chemical change, a change in appearance is the result of
the formation of a new material that has its own unique set of physical properties.
when there is a potential difference charges in the conductor flow from
the higher potential to the lower potential
A more familiar type of diode is
the light-emitting diode (LED).
Nanotechnology generally concerns
the manipulations of objects from 1 to 100 nanometers in size.
The Fahrenheit scale will become obsolete if and when the United States changes to
the metric system
The race thus began to squeeze more and more transistors together into tinier and tinier circuits. The scales achieved were in the realm of
the micron ( 10−6 m): thus the term microtechnology.
Technological advances have recently brought us past the realm of microns to the realm of
the nanometer ( 10^−9 m), which is the scale of individual atoms and molecules—a realm where we have reached the basic building blocks of matter.
One or more electrons from each metal atom are free to move throughout the atomic lattice. These charge carriers are called conduction electrons. Protons, on the other hand, do not move in a solid because they are bound within
the nuclei of atoms that are more or less locked in fixed positions.
An interesting discovery of nanoscience is that
the properties of a material at the level of its atoms can be different from its properties in bulk quantities.
The electric field about a proton extends radially from
the proton.
The circuit shown in Figure 8.30 illustrates the following characteristics of series connections:The voltage drop across each device is proportional to its resistance. This follows from Ohm's law expressed in the form V=IR . For constant current I, the voltage V is directly proportional to
the resistance R.
The circuit shown in Figure 8.31 illustrates the following major characteristics of parallel connections: Each device connects the same two points, A and B, of the circuit. The voltage is therefore
the same across each device.
A battery produces direct current in a circuit because the terminals of the battery always have
the same sign.
The circuit shown in Figure 8.30 illustrates the following characteristics of series connections:Electric current has a single pathway through the circuit. This means that the current passing through each electrical device along the pathway is
the same.
atom is used when speaking of
the submicroscopic particles in the sample.
The circuit shown in Figure 8.30 illustrates the following characteristics of series connections:The total voltage impressed across a series circuit divides among the individual electrical devices in the circuit so that the sum of the "voltage drops" across the resistance of each individual device is equal to the total voltage supplied by the source. This characteristic follows from the fact that the amount of energy given to the total current is equal to
the sum of energies given to each device.
The circuit shown in Figure 8.31 illustrates the following major characteristics of parallel connections:Current through the voltage source equals
the sum of the currents in its parallel branches.
The circuit shown in Figure 8.30 illustrates the following characteristics of series connections:This current is resisted by the resistance of the first device, the resistance of the second, and that of the third, so the total resistance to current in the circuit is
the sum of the individual resistances along the circuit path.
thermal energy is related to
the sum total kinetic energy of all of the particles in your sample
To prevent overloading in circuits, fuses are connected in series along
the supply line
The work that is done (by whatever means) in separating the opposite charges is available at
the terminals of the battery or generator.
Chalcogen properties
the top two elements of this group, oxygen and sulfur, are so commonly found in ores.
The circuit shown in Figure 8.30 illustrates the following characteristics of series connections:The current in the circuit is numerically equal to
the voltage supplied by the source divided by the total resistance of the circuit. This is in accord with Ohm's law.
What causes electric shock in the body—current or voltage? From Ohm's law, we can see that this current depends on
the voltage that is applied and also on the electrical resistance of the human body.
87. Give a reason why canal enthusiasts in Scotland appreciate the physics illustrated in Figure 5.16 (the block of wood floating in a vessel brimfilled with water).-
the weight of a filled vessel of water is the same no matter what floats in it. -Figure 5.16 shows that the weight of a filled vessel of water is the same no matter what floats in it. This is the basis of the Falkirk Wheel in Scotland ( Figure 5.17).
Different substances have different _______________ for storing energy
thermal capacities
Again, for emphasis: a substance does not contain heat—it contains
thermal energy.
When we measure something's temperature, we are really reading the temperature of the thermometer when it and the object have reached
thermal equilibrium
As the temperature of a substance increases, its molecules jiggle faster and move farther apart. The result is
thermal expansion
pecific heat capacity is like ____________ because it signifies the resistance of a substance to a change in temperature.
thermal inertia
Boyle's law example
tire
By translational we mean
to-and-fro linear motion
There are two main approaches to building nanoscale materials and devices:
top-down and bottom-up
The total positive charge balances the
total negative charge exactly
immersed
touching water
126.Count the tires on a large tractor
trailer that is unloading food at your local supermarket, and you may be surprised to count 18 tires. Why so many tires? (Hint: See Activity 35.)-126. This is because of Pascal's Principle which states that if a change in pressure occurs in any part of a fluid, that change is transmitted to every part of that fluid. This means that if the tractor trailer had a normal amount of wheels, the weight of the cargo would apply too much pressure on the tires to get them moving and would just push them onto the ground. This way with more wheels, the force will be divided equally into each of them and thus, the pressure will be less, so the tractor trailer can get moving.
Heat is thermal energy in
transit.
This device is made of
two strips of different metals welded together, one of brass and the other of iron. When heated, the greater expansion of the brass bends the strip.
submerged
under water
By becoming nanotechnology experts ourselves, we would be well equipped to
understand exact causes of nearly any disease or disorder (aging included) and empowered to develop innovative cures.
It is an absence of matter; it is a condition of nothingnes
vacuum
for a solid, we refer to how fast the particles move as they
vibrate and jiggle in place
90.Where on Earth might be a good place to find concentrated amounts of lithium salts?
volcanoes for their ash or creekbeds where salt is.
The unit of measurement for electric potential is the volt, so electric potential is often called
voltage.
Matter in the gaseous phase therefore occupies much more
volume than it does in the solid or liquid phase.
farenheit the number 212 is assigned to the temperature at which
water boils.
66.Many tongues have been injured by licking a piece of metal on a very cold day. Why would little harm result if one licked a piece of wood on the same day?
water in your saliva will freeze and stick your tongue on the pole
98.Your inventor friend proposes a design for cookware that allows boiling to take place below 100°C so that food can be cooked with less energy. Comment on this idea.
water is held together by pressure in the atmosphere. Take away lotta thermal energy in a vacuum or add lotta thermal energy to make it boil. If lower temperature, it would take twice as long to cook it. Less pressure, less temperature.
104.Discuss why halffrozen fruit punch is always sweeter than completely melted fruit punch.-
water is in form of ice crystals. Only taste syrup
-Liquid Pressure Formula
weight density*depth
Formula for weight density
weight/volume
moves closer to the nucleus and the energy lost from the electron is emitted from the atom as a photon of light.
when a high-potential-energy electron in an atom loses some of its energy, the electron
absorbing energy;one of the electrons.
when an atom absorbs a photon of light, it is__________. This energy is acquired by ____________
102.Distinguish between melting and freezing in terms of molecular speeds.
when melting, movement increased. When freezing molecules are still and in a fixed position.
94.Double pane windows have nitrogen gas or very dry air between the panes. Why is using ordinary air between the panes a poor idea?-
when window cooled, condesnation happens. moisture is a conductor, so it will allow more enrgy through it.
This means that the charge of the object is a
whole number multiple of the charge of an electron.
The nonmetallic elements,
with the exception of hydrogen, are on the right side of the periodic table.
If we push a particle with twice the charge, we do twice as much
work
Heat can be made to flow the other way only when
work is done on the system or by adding energy from another source.
82.Does a shell have to contain electrons in order to exist?
yes. a shell is not actually real, it is morely a border to show where regions of exletcrons reside. without ekectrosn, no shell
The numbers of electrons and protons balance, so whether a wire carries a current or not, the net charge of the wire is normally
zero at every moment.
Atoms usually have as many electrons as protons, so the atom has
zero net charge.
Static charge on the surface of any electrically conducting surface arranges itself such that the electric field inside the conductor cancels to
zero.
The Greek capital letter omega, ________, is commonly used as the symbol for the ohm.
Ω
