Constructed Response CSET Sciences Domain 1

3. What is matter, and what are its properties?

Anything that takes up space or has a mass of any kind is matter. Everything you can touch is made of matter. If it is made of anything, that anything is matter. Matter has many properties. It can have PHYSICAL properties like different densities, melting points, boiling points, freezing points, color or smells. There are also CHEMICAL properties that define matter. A good example of chemical properties is the way elements combine with each other in reactions. The big thing to remember... Matter can change in two major ways, physically and chemically. Phase describes a PHYSICAL state of matter. The key word to notice is physical, because things only move from one phase to another by physical means. If energy is added (like increasing the temperature or increasing pressure) or if energy is taken away (like freezing something or decreasing pressure) those are physical changes. Those kinds of forces change states of matter.

7. Why do deciduous trees lose their leaves in the fall?

Each year in northeast United States, nature undergoes a change during the months of October and November,. Days become shorter and temperatures become cooler. The most noticeable change, however, is fall foliage, the change of the colors of leaves. They turn from rich greens, to golden yellows, to bright reds and oranges, and even deep purples. This annual color change phenomenon is the result of a biological structure called a pigment. A pigment is defined as any coloring matter present in an organism from the color of hair to the color of rose petals. The green pigment present in plants is chlorophyll. The function of chlorophyll is to absorb sunlight for the plant to convert carbon dioxide and water to sugars that the plant may use as its energy source. This process is known as photosynthesis. When the weather gets cooler and days get shorter, a plant recognizes that it is wasting valuable energy in producing chlorophyll. Photosynthesis slows down due to the lower temperatures that affect chemical reactions. Also, less water is available during these freezing months for the plant to function normally. The chlorophyll slowly disappears, revealing other pigments that are already present in the leaves. These deciduous trees eventually lose their leaves in preparation for the winter

4. Discuss the relationship between motion and force.

Force is any outside influence that changes the velocity of an object. If this seems too simple, consider what forces propel you forward when you start to walk. When you stop walking, other forces stop you. In other words, your velocity starts at zero, increases to a maximum, and then decreases until it reaches zero again. What are these forces acting on you? Consider how your muscles react and how your feet press the ground. Does the ground return the favor and press your feet upward? Read on, brave physicist and find out. This change in velocity due to a force, if you will please recall, results in what? Of course you answered "Acceleration". Now, if the velocity remains constant (there is no acceleration), then the net force on the object is zero. In case you missed it, this is only for constant velocity or zero acceleration. All other cases do not apply here. Again, if you didn't notice the bold words a few sentences ago, this is an important concept. Now, likewise, if an object has constant velocity or has no velocity (it is at rest), then this object is in equilibrium. While we're at it, a force can be further broken down into smaller categories. A contact force is a force that is transferred from one object to another. For example, the hitting of a soccer ball transfers force from the foot of the player to the ball through physical contact. Another kind of force is the field force. A field force does not require contact to transfer to an object. Gravity is the classic example of this. You do not need to be in direct contact with the earth to feel its gravity. If you fall out of a plane, the gravitational force will pull you toward the earth even if you are miles away from the surface. Likewise, the tides on earth are caused mainly by the gravitational tug of the moon despite its great distance from the earth. The fundamental forces of nature are all field forces and describe almost all of the known force interactions in the universe. In order of increasing strength, they are: gravity, the weak nuclear force, electro-magnetism, and the strong nuclear force.

9. In trying to lift a heavy stove into a moving truck, a worker utilizes rope, a rug, and two long planks of wood. Identify what forces are at work in making it too hard for the worker to just lift the stove up on his back. Draw a picture and explain the process. (This question, or something like it, appeared on the most recent CSET.)

If the worker was using Normal force Nf, the stone would be perpendicular to the man, making it to difficult to lift ┴. If the worker were to use an inclined plane one of the simple machines he could gain an mechanical advantage, save energy and make the work easier. Attach the rope to the rug. Put the boulder on the rug. Put the rug underneath the planks of wood. Put the planks up on the truck. Use the rope to pull the boulder up. Note: this is definitely on the right track. This correctly identifies the inclined plane as the key concept. I'll quote from the wonderful book, the way things work, that I've recommended earlier. "the ramp makes life easier not by altering the amount of work that is needed, but by altering the way in which the work is done. Work has two aspects to it: the effort that you put in, and the distance over which you maintain the effort. If the effort increases, the distance must decrease, and vice versa." Using this same principle, that is why steep trails use switchbacks rather than climbing straight up the mountain. The rope allows you to set up a pulley, which allows you to use your body weight as an asset rather than a detriment. Finally, the rug can be used to decrease friction on the inclined plane.

5. Briefly summarize Newton's three Laws of Motion.

Newton's First Law of Motion: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. What this means is that if you leave a book on your coffee table over night, when you return in the morning, unless an outside force moved it, it will be in the same place. This also means that if you kick a soccer ball, it will continue moving until it hits something. However we all know the ball will eventually stop even if it does not hit a wall - this is because of the friction between the ball and the ground, and between the ball and the air. One of the most common places people feel the First Law is in a fast moving vehicle, such as a car or a bus, that comes to a stop. An outside force stops the vehicle, but the passengers, who have been moving at a high speed, are not stopped and continue to move at the same speed. Newton's Second Law of Motion: can be expressed by an equation. Acceleration= Force/Mass. This is usually shortened to A=F/M or F=MA. Newton's Second Law is more abstract than the First. The Second Law governs all acceleration and is really very simple - acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). Everyone unconsciously knows the Second Law. Everyone knows that heavier objects require more force to move the same distance than do lighter objects. The Second Law, however, gives us an exact relationship between force, mass, and acceleration. Newton's Third law is probably the most famous of his laws it is, "Every action has an equal and opposite re-action" These actions are forces, so you can remember this law as being every force has an equal and opposite force. Remember that these are two separate forces, which act upon two separate objects, and so they do not cancel each other out. The Third Law at first seems simple, but is a very important law. Every time we interact with our surroundings we feel the Third Law. When you punch someone in the face, your hand not only applies a force to the person's face; the person's face applies a force to your hand. Since the person's face is softer than your hand it suffers more from the interaction. The Third Law is very important for space travel. In the cold void of space there is no air for jets to suck or for propellers to churn, and yet space ships can maneuver in a vacuum. How do they do it? The engines propel gas particles out the back of the space ship. Since every force has an equal and opposite reaction force, the space ship will be propelled forwards. Because of the First Law space ships do not need very much fuel - once they are moving they will stay in motion

8. Identify six renewable (as opposed to depleted) sources of energy.

Renewable energy systems use resources that are constantly replaced and are usually less polluting. Examples of renewable energy systems include, hydroelectricity, Organic matter, geothermal energy, tidal power, solar energy, and wind energy. Hydroelectricity is electrical energy produced from water stored in dams or flowing in rivers and streams. When electricity is required stored water is released and flows through a turbine, which is connected to an electric generator, generating electricity. The volume of water flowing through the turbine and the vertical distance it falls determines the amount of electricity produced. The larger the volume and the higher the vertical distance, the greater the amount of generation. Organic matter can be a source of energy when it is burnt or used to produce alcohol or gas (biogas) fuels. Biomass energy can originate from plant or animal material, waste from agriculture or forestry products, or human waste, or animal waste. Some examples of biomass products are: In Queensland, sugar cane waste (bagasse) is being burnt to power some sugar mills. Bagasses, and wheat starch in New South Wales, are being used to produce ethanol. Ethanol can be mixed with petrol or diesel to run existing motor vehicles. In a 1-to-10 ratio with petrol or a 3-to-20 ratio with diesel, engines don't need to be modified and carbon monoxide and CO2 emissions can be reduced. Biogas from a Melbourne sewerage plant is being used to fuel small power stations in Victoria Geothermal heat energy is available in the most geologically unstable regions of the world. This form of energy is derived from heat that originates within the Earth where parts of the Earth's crust are separating, colliding or sliding past each other in a shearing motion, within the seismic belt. Geothermal heat energy can be used directly. For example heating water for bathing and cleaning. Geothermal heat energy can also be used indirectly. For example geothermal steam may be used to drive steam turbines which in turn produce electricity. Tidal Power The gravitational attraction of the sun and the moon causes water to flow around the Earth following the position of the sun and moon. Tides result from this gravitational attraction. If the change in tidal levels between high and low tides are of a great enough magnitude (ideally over 4 meters), turbines similar to those in hydropower stations can be utilized to generate electricity. The process works by storing the water at high tide, and then at low tide the water is released and directed through the electricity producing turbines. Solar Energy: Sunlight from the sun can be converted into electricity either directly or indirectly. Solar cells, otherwise known as photovoltaic cells, convert the sun's radiant energy directly into electricity, while indirectly high temperature solar thermal collectors can produce steam to operate an engine or moves a turbine to drive a generator. Low temperature solar thermal collectors can also be used to provide hot water. Wind Energy: Wind energy has been used for centuries as an energy source for sailing ships, pumping water and grinding grain (the latter two are accomplished through the use of windmills). Winds result from the unequal heating of the Earth and its atmosphere by the sun. Air circulates from cool to warm areas as the sun heats different parts of the Earth at different rates, producing wind (convection currents). In addition, planetary winds flow in a circular pattern due to an effect known as the Coriolis, force which is due to the rotation of the Earth. Wind Energy is harnessed by wind generators (windmills).

1. What is heat energy? Where does it come from, and what are its properties? Include in your discussion the following terms: molecules, conduction, convection, and radiation.

The Universe is made up of matter and energy. Matter is made up of atoms and molecules (groupings of atoms) and energy causes the atoms and molecules to always be in motion - either bumping into each other or vibrating back and forth. The motion of atoms and molecules creates a form of energy called heat or thermal energy which is present in all matter. Even in the coldest voids of space, matter still has a very small but still measurable amount of heat energy. Energy can take on many forms and can change from one form to another. Many different types of energy can be converted into heat energy. Light, electrical, mechanical, chemical, nuclear, sound and thermal energy itself can each cause a substance to heat up by increasing the speed of its molecules. So, put energy into a system and it heats up, take energy away and it cools. For example, when we are cold, we can jump up and down to get warmer. Mechanical energy is converted into thermal energy whenever you bounce a ball. Each time the ball hits the ground, some of the energy of the ball's motion is converted into heating up the ball, causing it to slow down at each bounce. Thermal energy can be transferred to other objects causing them to heat up. When you heat up a pan of water, the heat from the stove causes the molecules in the pan to vibrate faster causing the pan to heat up. The heat from the pan causes water molecules to move faster and heat up. So, when you heat something up, you are just making its molecules move faster. There are many examples of how heat can be converted. One example is chemical energy from the foods we eat is converted into heating our bodies. Light from the sun is converted to heat as the sun's rays warm the earth's surface. Energy from friction creates heat. For example when you rub your hands, sharpen a pencil, make a skid mark with your bike, or use the brakes on your car, friction generates heat. The more energy that goes into a system, the more active its molecules are. The faster molecules move, the more heat or thermal energy they create. So, the amount of heat a substance has is determined by how fast its molecules are moving, which in turn depends on how much energy is put into it. Convection is the transfer of heat by the actual movement of the warmed matter. Heat leaves the coffee cup as the currents of steam and air rise. Convection is the transfer of heat energy in a gas or liquid by movement of currents. (It can also happen is some solids, like sand.) The heat moves with the fluid. Consider this: convection is responsible for making macaroni rise and fall in a pot of heated water. The warmer portions of the water are less dense and therefore, they rise. Meanwhile, the cooler portions of the water fall because they are denser. Conduction is the transfer of energy through matter from particle to particle. It is the transfer and distribution of heat energy from atom to atom within a substance. For example, a spoon in a cup of hot soup becomes warmer because the heat from the soup is conducted along the spoon. Conduction is most effective in solids-but it can happen in fluids. Fun fact: Have you ever noticed that metals tend to feel cold? Believe it or not, they are not colder! They only feel colder because they conduct heat away from your hand. You perceive the heat that is leaving your hand as cold. Radiation: Electromagnetic waves that directly transport ENERGY through space. Sunlight is a form of radiation that is radiated through space to our planet without the aid of fluids or solids. The energy travels through nothingness! Just think of it! The sun transfers heat through 93 million miles of space. Because there are no solids (like a huge spoon) touching the sun and our planet, conduction is not responsible for bringing heat to Earth. Since there are no fluids (like air and water) in space, convection is not responsible for transferring the heat. Thus, radiation brings heat to our planet

6. Discuss the organization of the Periodic Table of the Elements. How is the table organized? What information is included in each square on the table? What is the significance of the columns?

The periodic table is organized like a big grid. The ELEMENTS are placed in specific places because of the way they look and act. If you have ever looked at a grid, you know that there are ROWS (left to right) and COLUMNS (up and down). The periodic table has rows and columns too and they each mean something different. When you look at the periodic table the rows are different colors. Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows are considered to be different PERIODS. In the periodic table, elements have something in common if they are in the same row. All of the elements in a period have the same number of atomic SHELLS. We talk about shells when you go look at the elements in detail. Every element in the top row (the first period) has one shell for its electrons. All of the elements in the second row (the second period) have two shells for their electrons. It goes down the periodic table like that. At this time, the maximum number of shells is seven. The periodic table has a special name for its columns too. When a column goes from top to bottom, it's called a GROUP. The elements in a group have the same number of electrons in their outer shell. Every element in the first column (group one) has one electron is its outer shell. Every element on the second column (group two) has two electrons in the outer shell. As you keep counting the columns and you'll know how many electrons are in the outer shell. You'll may notice that HYDROGEN is special. Hydrogen can have the talents and electrons of two groups, one and seven. To scientists, Hydrogen is sometimes missing an electron, and sometimes it has an extra. HELIUM is another exception. Helium is different than all of the other elements. It can only have two electrons in its outer shell. Even though it only has 2 it is still grouped with elements that have eight. The elements in between, with the grey color, are called TRANSITION elements. They have special electron rules.

2. Describe the three basic fossil fuels and how they were formed.

There are three basic kinds of fossil fuels: All three are the altered products of decomposed plant and animal material, preserved for millions of years in the Earth. Most of the world's energy (85%) comes from fossil fuels, which includes: coal, oil and natural gas. Fossil fuels were formed many hundreds of millions of years ago through the photosynthesis of organic matter in the Carboniferous period-getting its name from carbon-which is the basic element in the fossil fuels. Energy can be derived from fossil fuels through the process of burning them in the presence of oxygen. Heat can be used directly or indirectly by driving turbines to produce electricity. Petroleum was formed gradually through the decomposition of organic matter, such as aquatic plants and animals that took place hundreds of millions of years ago and became entrapped in beds of porous rock. A number of these accumulations of petroleum are referred to as reservoirs and a series of reservoirs are known as a field. A group of fields in a single environment is referred to as a sedimentary basin. •Petroleum: Petroleum products come from crude oil, which is pumped from underground. Crude oil is refined to remove impurities and extract particular chemical components. In a refinery, different components are separated in a large column by distillation. The products include butane, propane, octane (all hydrocarbon fuels), kerosene, and other chemicals. Petroleum products come from crude oil, which is pumped from underground. Crude oil is refined to remove impurities and extract particular chemical components. In a refinery, different components are separated in a large column by distillation. The products include butane, propane, octane (all hydrocarbon fuels), kerosene, and other chemicals. •Coal: Coal is a solid fossil fuel. More than half of the electrical power produced in the United States comes from coal-fired plants. Coal is mined in two ways: 1) surface mining and 2) deep mining. In surface mining, the coal is close to the surface, so the upper layer is scraped away, revealing the coal below. In deep mining, large pits or mines are dug deep into the earth so that machines and people can get to the coal. Coal is primarily used to generate electricity, but one coal by-product, coke, is essential for producing steel. Heating coal to very high temperatures makes Coke. When the coke is burned, it reaches high enough temperatures to melt iron ore and turn it into steel. Although it is common and inexpensive, coal has many environmental side effects. When coal is burned, it produces a lot of ash and soot, getting into the air and our lungs. •Natural Gas: Natural gas is made up of methane (CH4), along with some additives. It is colorless and odorless, and very clean burning. Unlike coal or petroleum, natural gas does not produce particulate matter when burned. Like other fossil fuels, it still releases CO2 as product. Natural gas is used to heat homes, power vehicles, generate electricity, and as a raw material for producing many products. Just like oil, natural gas is removed from the ground by pumps and then refined. During the refining process an odorant is added so that gas leak can be detected. Some by-products of natural gas include butane and propane, which are also used as fuels

10. Describe the process by which the human ear perceives sound.

Your ears are in charge of collecting sounds, processing them, and sending sound signals to your brain. And that's not all - your ears also help you keep your balance. So if you bend over to pick up your cat, you won't fall down - or even worse - fall on your cat. Meow! The ear is made up of three different sections: the outer ear, the middle ear, and the inner ear. These parts all work together so you can hear and process sounds. The pinna is the visible part of the ear that resides outside of the head. We often use the pinna, also called the auricle, for hanging earrings and resting eyeglasses, but the primary purpose of the pinna is to collect sound. It does so by acting as a funnel, amplifying the sound and directing it to the ear canal. While passing through the pinna, sound also goes through a filtering process in which sounds in the frequency range where human speech is normally found are enhanced. Finally, the filtering process also adds directional information to the sound. The outer ear also includes the ear canal, where wax is produced. Earwax is that gunky stuff that protects the canal. Earwax contains chemicals that fight off infections that could hurt the skin inside the ear canal. It also collects dirt to help keep the ear canal clean. So earwax isn't just gross. It's gross and useful. After sound waves enter the outer ear, they travel through the ear canal and make their way to the middle ear. The middle ear's main job is to take those sound waves and turn them into vibrations that are delivered to the inner ear. To do this, it needs the eardrum, which is a thin piece of skin stretched tight like a drum. The eardrum separates the outer ear from the middle ear and the ossicles. The ossicles are the three tiniest, most delicate bones in your body. They include the malleus, which is attached to the eardrum and means, "hammer" in Latin. The incus, which is attached to the malleus and means "anvil" in Latin. The stapes the smallest bone in the body, which is attached to the incus and means "stirrup" in Latin. When sound waves reach the eardrum, they cause the eardrum to vibrate. When the eardrum vibrates, it moves the tiny ossicles - from the hammer to the anvil and then to the stirrup. These bones help sound move along on its journey into the inner ear. Sound comes into the inner ear as vibrations and enters the cochlea a small, curled tube in the inner ear. The cochlea is filled with liquid, which is set into motion, like a wave, when the ossicles vibrate. The cochlea is also lined with tiny cells covered in tiny hairs that are so small you would need a microscope to see them. They may be small, but they're awfully important. When sound reaches the cochlea, the vibrations (sound) cause the hairs on the cells to move, creating nerve signals that the brain understands as sound.