ISAT 100 Test #2

Group # on periodic table = ?

# of valence electrons

What is the difference between a parallel circuit and a series circuit? Which type of circuit is used in our homes? Why? (5.6)

A series circuit has components that are connected end-to-end in a single that forms one path electrons can flow on. A parallel circuit is one where the components are connected across from each other. This forms two sets of electrically common points. Our homes use a parallel circuit because if it used a series circuit everything would have to be run at the same time (i.e. heater, oven, lights etc.). Parallel allow you to use switches to turn off/on objects you wish to run electricity to.

What is the "smart grid"? How may it impact performance of our electric grid? (Lecture)

A smart grid is one that communicates between the utility company and the customer. What makes it a smart grid is the sensing along the transmission line. It may impact performance because it is more efficient along transmission lines by integrating renewable energy systems , quicker responses to power outages, and lower costs for consumers.

Describe an electric transformer. What role does it play in our electric distribution system? (5.5)

A transformer is a device that either increases or decreases AC current and voltage. As power flows to more urban areas, electric companies use transformers to reduce the voltage for safety reasons. Power in = Power out Number of coils to voltage Vp/Np = Vs/Ns

3. What is AQI? How is it used to communicate unhealthy conditions? (7.4)

AQI stands for Air Quality Index. It is color coded in six different intervals ranging from good to hazardous. These intervals communicate to people whether or not the air in the area is healthy to breathe.

What is an electric field? How does it relate to the movement of electrons in a conductor? (Review fig. 5.14 as you answer these questions.) (5.1)

An electric field is a force field produced by an electric charge. Any charged object, whether positive or negative creates an electric field that occupies the space surrounding it. A conductor allows electrons to move freely from atom to atom.

Describe electric motors and electric generators. How are they different? (5.5)

An electric motor converts mechanical energy into electrical energy. While an electric generators convert electrical energy into mechanical energy. Electric motors obey the "Fleming's Left Hand Rule", which differs from electric generators which obey " Fleming's Right Hand Rule".

Heating vs. cooling

An increase in the internal energy A decrease in the internal energy

These gases are found in the atmosphere in small amounts: CH4, SO2, and O3. Give the name of each of these gasses and describe the number and types of atoms present in each. (7.8)

CH4 = Methane, one carbon atom and 4 hydrogen atoms SO2 = Sulfur Dioxide, 1 sulfur atom and 2 oxygen atoms O3 = Ozone, 3 oxygen atoms

When balancing equations start with

Carbon, then hydrogen, then oxygen

Direct Current (DC) vs. Alternating Current (AC)

Charges move in one direction, Ex: electronic batteries, solar cells Travels back and Forth Practically all generated electricity Stepped down for use in homes and industry IpVp = IsVs

In general, which groups of people are the most sensitive to ozone?

Children, the elderly, those with lung diseases, very active people, and those with a genetic predisposition may be more sensitive to ozone.

What are CFCs? How do they contribute to Cl· concentrations in the atmosphere? (8.9)

Chlorofluorocarbons. They release Cl that interacts with ozone in the atmosphere.

Explain how the small changes in Cl· concentrations (measured in parts per billion) can cause the much larger changes in O3 concentrations (measured in parts per million). (8.9)

Cl acts as a catalyst. A catalyst is essentially the idea that a substance increases the reaction of another. In this chemical reaction, the substance doesn't change much in chemical composition. There are a series of reactions in which O3 reacts with Cl to produce O2. This fosters the breakdown of O3, or the ozone.

Most primary pollutants come from

Combustion - rapid combination of oxygen with another substance

Q = mLf

One of the responses of matter to heat - Phase change at a constant temperature. (Latent heat) Heat = mass x latent heat of fusion Units used: m - grams, latent heat of fusion - cal/gC°

Q = mLv

One of the responses of matter to heat - Phase change at a constant temperature. (Latent heat) Heat = mass x latent heat of vaporization Units used: m - grams, latent heat of vaporization - cal/gC°

The EPA characterizes ozone as "good up high, bad nearby." Explain. (7.12)

Ozone occurs in two layers of the atmosphere. The layer closest to the Earth's surface is the troposphere. Here, ground-level or "bad" ozone is an air pollutant that is harmful to breathe and it damages crops, trees and other vegetation. The troposphere generally extends to a level about 6 miles up, where it meets the second layer, the stratosphere. The stratosphere or "good" ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays.

Concentration Terms pph ppm ppb

Parts per hundred = percent Ex: 21 oxygen molecules per 100 molecules and atoms in air Parts per million 1 x 10^6 molecules and atoms in air Parts per billion 1 x 10^9 molecules and atoms in air

4. Radon is one of the noble gases found in Group 8A on the periodic table. Which properties does it share with the other inert gases? In which way is it distinctly different? (7.6)

Radon, like the other noble gases, undergoes few, if any, chemical reactions. Radon is radioactive, which is a trait that distinguishes it from the other noble gases.

Define "risk assessment" and describe the roles that toxicity and exposure play? (7.3)

Risk assessment is the process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome. The risks presented by an air pollutant are a function of both: toxicity, the intrinsic health hazard of a substance, and exposure, the amount of the substance encountered.

Describe and explain the Chapman Cycle. (8.6)

See slide 21 on Chapter 8 *****

Describe the difference between single bonds, double bonds, and triple bonds. (8.3)

Single bonds are formed when two electrons (one pair) are shared between atoms. Double bonds are formed when there are two pairs of shared electrons. Triple bonds are formed when there are three pairs of shared electrons.

Describe the three phases of matter and compare the relative kinetic energy of the molecules in each phase. (4.1)

Solids have definite shapes and volumes because they have molecules that are nearly fixed distances apart and bound by relatively strong cohesive forces. In a solid, molecules vibrate around a fixed equilibrium position and are held in place by molecular forces. Liquid molecules are not confined to an equilibrium position. In a liquid, molecules can rotate and roll over one another because the molecular forces are not as strong. Gases do not have fixed shape or fixed volumes. In a gas, molecules move rapidly in random, free paths.

Describe static electricity. How is it different from electric current? (5.1 & 5.2)

Static electricity is a stationary charge that is confined to an object. This is different from an electric current which is allowed to move along a defined path.

Define Temperature. (4.2)

Temperature is the measure of the average kinetic energy of the molecules making up a substance. The more common definition is simply how hot or cold something is.

Heat engine

device that converts heat into mechanical energy

A heat pump is able to move heat from a cooler region to a warmer region by

evaporating a refrigerant where you want it cooler, and then condensing it elsewhere

Air is a

mixture

Combined Heat and Power Unit

runs off natural gas heat comes from waste heat

Thermodynamics

the study of heat and its relationship to mechanical and other forms of energy.

Step up vs. step down transformers

up: secondary side is higher, more loops on secondary side down: primary side is higher, more loops on primary side

7. Express each of these numbers in scientific notation. (7.3; End Matter sec. A.5 Scientific Notation) 1. 0.0000075 m, the diameter of a red blood cell 2. 150,000 mg of CO, the approximate amount breathed daily

7.5 × 10 ^-6 m 1.5 x 10^5 mg

8. Write each of these values as a "regular" number. (7.3; End Matter sec. A.5 Scientific Notation) a. 8.5 × 10^4 g, the mass of air in an average room b. 2.1 × 10^8 gallons, the volume of crude oil spilled into the Gulf of Mexico in 2010

85,000 g 210,000,000 gallons

5. The concentration of argon in air is approximately 0.9%. Express this value in ppm. (7.2)

9000 ppm

Define and contrast calorie, kilocalorie, Calorie, and BTU. (4.3)

A calorie (cal) is the amount of energy (or heat) needed to increase the temperature of 1 gram of water 1 degree Celsius. One kilocalorie (kcal) is the amount of energy (or heat) needed to increase the temperature of 1 kilogram of water 1 degree Celsius. A Calorie the measure of the energy released by the oxidation of food is called the Calorie by nutritionists, but it is the same as a kilocalorie. The English system's measure of heating is called the British Thermal Unit (BTU). One BTU is the amount of energy (or heat) needed to increase the temperature of 1 pound of water 1 degree Fahrenheit.

What are some of the more important safety features in a household electrical circuit? How do they work? (5.6)

A circuit breaker is used to control the amount of current that flows through household circuits. When too much current flows to an object, the circuit breaker will immediately shut off that current stopping anything too dangerous from happening. These can be reset after the fact. There is also dedicated ground three-prong plugs. The middle prong is connected directly to the ground so if a short circuit occurs the current goes directly to the ground instead of from you to the ground.

Microgrid

A microgrid generally operates while connected to the grid, but importantly, it can break off and operate on its own using local energy generation

Define and contrast "primary pollutants" versus "secondary pollutants". Give an example of each. (7.11; 7.12)

A primary pollutant is from a direct source while a secondary pollutant involves chemical reactions involving multiple pollutants. An example of a primary pollutant would be sulfur dioxide from coal. An example of a secondary pollutant would be ozone.

What is a semiconductor? Give some example elements that exhibit this characteristic. (Lecture)

A semiconductor can conduct/insulate electricity under certain conditions. Semiconductors can be used in computer chips and solar cells.

Speed of light formula

c = wavelength x frequency 3.00 x 10^8 m/s

In the U.S. there are how many interconnected grids and what are they called?

3 interconnected grids Western, Eastern, ERCOT

In a tropical rain forest, the water vapor concentration may reach 50,000 ppm. Express this as a percent. (7.2)

5%

Average human breaths about how much air per day?

20 kg/day

A food Calorie is

1,000 calories, a kilocalorie, measure of chemical energy released by the oxidation of food

Using the periodic table as a guide, specify the number of protons and electrons in a neutral atom of each of these elements. (8.2) 1. oxygen (O) 2. nitrogen (N) 3. magnesium (Mg) 4. sulfur (S)

1. Protons: 8, Electrons: 8 2. Protons: 7, Electrons 7 3. Protons: 12, Electrons: 12 4. Protons: 16, Electrons: 16

Two heating methods

1. Temperature Difference - energy always moves from higher temperature regions to lower temperature regions. 2. Energy form conversion - transfer of heat by doing work.

On a molecular level, how does the condensation of water vapor on a bathroom mirror warm the bathroom?

1. The latent heat is released during liquid to vapor phase changes 2. The latent heat of vaporization is released from decreased molecular potential energy

Ultraviolet radiation is categorized as UV-A, UV-B, or UV-C. Arrange these types in order of increasing: (8.6) 1. Wavelength 2. Energy 3. Potential for biological damage **See slide 8 on Ch.8

1. UV-C < UV-B < UV-A 2. UV-A < UV-B < UV-C 3. UV-A < UV-B < UV-C

Define and contrast the three forms of heat flow/transfer presented in the chapter. (4.3)

Conduction is the transfer of energy from molecule to molecule, or heat flowing through matter. Direct physical contact is required and it can't happen in a vacuum. Ex: poor conductors are insulators such as styrofoam, wool, air Convection is the transfer of heat by an energy transfer through the bulk motion of hot material. Hot air rises. Ex: Space heater, Gas furnace. Convection happens in liquids and gases, while conduction mainly occurs in solids. Radiation is the third form of heat flow, and it involves energy associated with electromagnetic waves. All objects emit and absorb radiation. Can operate in a vacuum. Ex: Global Climate Change

21% means 21 parts per hundred 210 parts per thousand 2,100 parts per ten thousand 21,000 parts per hundred thousand 210,000 parts per million

Difference between pph and ppm is a factor of 10,000

How are electric conductors different from electric insulators? What are some examples of each? (5.2)

Electric conductors are different than electric insulators. In an electric conductor, the electrons are free to move throughout the material. In addition, the charge dissipates which means the charge essentially scatters away. However, the insulator's added charge remains on the object. Regarding electrons, in an insulator the motion is restricted. Examples of electric conductors are metals and graphite. Examples of insulators are glass, wood, and diamond.

Describe electric current. What units do we use to measure it? (5.2)

Electric current is the flow of charge and is measured by charge moved divided by time. This is measured in amps.

Describe electric potential difference. What units do we use to measure it? (5.2)

Electric potential difference is equal to work divided by charge moved. This is measured in volts.

Describe electric resistance. What units do we use to measure it? (5.2)

Electric resistance is volts divided by current. This is measured in Ohms.

What is the definition of electrical work? Of electrical power? What units do we use for each? (5.2)

Electrical work is the work done on a charged particle by an electrical field. The SI unit of work is a Joule (J). Electrical power is the rate at which electrical energy is transferred by an electric circuit. The unit for power is a Watt (W).

Describe electromagnetic induction. How do we use it to generate electricity? (5.5)

Electromagnetic induction describes the overall interaction of how a loop of a wire is moved or changed in a magnetic field, a voltage is started in the wire. This induced voltage results in an induced current. We use this to generate electricity through a generator. The generator is essentially an axle with many wire loops that rotates in a magnetic field. The axle is powered by mechanical energy and then a current is induced in the coil.

State in your own words the second law of thermodynamics. (4.5)

Energy allows heat to flow from hotter objects to cooler objects.

See heat engine vs. heat pump models on slide 14 Ch. 4****

Engine - arrows moving from high temperature down to low temperature Pump - arrows moving up from low temperature to high temperature, work is imputed to move energy from cold region to hot region

Define and contrast heat and internal energy. (4.3)

Heat is a form of energy transfer between two objects. Another definition of heat is the measure of the internal energy that has been absorbed by or transferred from an object. Internal energy is the total kinetic energy of an object.

State in your own words the first law of thermodynamics. (4.5)

Heat is the energy supplied to a system, and heat minus the work performed on the system equals the change in the internal energy.

Review Example 4.7 and be sure all your teammates can solve this type of problem. ***On Ch. 4 Powerpoint

How much energy does a refrigerator remove from 100.0g of water at 20.0 degrees C to make ice at -10.0 degrees C?

11. Hydrocarbons are important fuels that we burn for many different reasons. (7.8) 1. What is a hydrocarbon? 2. Rank these hydrocarbons by the number of carbons they contain: propane, methane, butane, octane, ethane.

Hydrocarbons are compounds made up of only the elements hydrogen and carbon. Methane - 1 carbon, Ethane - 2 carbons, Propane - 3 carbon atoms, Butane - 4 carbon atoms, octane - 8 carbon atoms

Why is indoor air quality so important? (As you answer this question think about the main components of risk assessment - toxicity and exposure.) (7.13)

Indoor air quality is very important because it has a big significance on our health. Many people spend a lot of time indoors. There is a lack of adequate ventilation which can cause pollutants to stay put. Examples of indoor pollutants are paint fumes, carbon monoxide, and nitrogen dioxide. Often times, indoor air quality can be worse than outdoor. The toxicity is much higher at concentrated levels and without adequate ventilation. In addition, individuals are exposed much longer because of staying indoors longer.

What is distributed electrical generation? How may it impact performance of our electric grid? (Lecture)

It is the power generation at the point of consumption, meaning the power is generated on site vs centrally. It eliminates cost, complexity, inter-independent, and inefficiencies associated with transmission and distribution. It may impact our electric grid by using storage and advanced renewable technologies which can help in the transition to a smarter grid.

The Chapman Cycle can be used to model the concentration of what substance. The Chapman Cycle describes a process said to be in steady state. What does steady state mean in this context? (8.6)

It measures the concentration of stratospheric ozone. Steady state means that the concentration of ozone remains constant and there is no net change in concentration.

Why did Tesla's design for commercial electrical grids win over Edison's design? (Lecture)

It was cheaper than Edison's design. You could have electricity flow at high voltages across land to save money and then reduce the voltage in populated areas using transformers.

What is magnetism and what are some sources? (5.3)

Magnetism refers to physical phenomena arising from the force caused by magnets, objects that produce fields that attract or repel other objects. A naturally occurring black iron oxide mineral called magnetite attracts substances such as iron, steel, cobalt and nickel. Substances that are attracted have magnetic properties, and substances that are repelled are referred to as "nonmagnetic"- but all nonmagnetic materials are either slightly repelled or slightly attracted by strong magnets

Mixtures vs. compounds vs. elements (see slide 28 Ch.7)**

Matter divided into pure substances and mixtures, Pure substances divided into elements and compounds

Review Figure 4.17 with your teammates. Identify the processes in which water absorbs energy from the surroundings. Identify the processes in which water releases energy to the surroundings. ***Found on slide 20 of Chapter 4

Melting and Evaporation - Energy absorbed and increased molecular potential energy Condensation and Freezing - Energy released and decreased molecular potential energy

These gases are found in the troposphere: CO2, CO, O2, Ar, and N2. (7.1; 7.2) a. Rank them in order of their abundance in the troposphere. b. For which of these gases is it convenient to express its concentration in parts per million?

N2 = 78%, O2 = 21%, Ar = 0.9%, CO2 = 0.04%, CO Carbon Dioxide

How do we derive Ohms Law from the model for electrical resistance? How do we apply the Ohms Law model? (5.2)

Ohm's law is derived from this model as it shows the relationship between voltage, current, and resistance. Ohm's law model can be applied to DC conductors, which depend upon material, length, diameter, and temperature.

Q = mc∆T

One of the responses of matter to heat - 1. Temperature increase within a given phase. Specific heat formula, Different materials require different amounts of heat to produce the same temperature change- measured by specific heat Heat = mass x specific heat x the change in temperature Units used: m - grams, specific heat - cal/gC°, Temperature - C° Heat - kcal

Compare and contrast the three temperature scales presented in the chapter. (4.2)

The Fahrenheit scale is based on the freezing and boiling points of water at normal atmospheric pressure. There are 180 equal intervals, or degrees, between the freezing point at 32 degrees and the boiling point at 212 degrees on the Fahrenheit scale. The Celsius scale measures the freezing point of water at 0 degrees celsius and the boiling point of water at 100 degrees celsius. There are 100 equal reference points on the the celsius scale, which is why it is often called the centigrade scale. The Kelvin Scale is an absolute temperature scale that does not have arbitrarily assigned reference points, and absolute zero is the lowest temperature possible. ***See image in textbook

What is the Montreal Protocol? What did it achieve? Why is it considered to be such a monumental achievement? (8.11)

The Montreal Protocol was a treaty that set a timetable for phasing out the production of CFCs, which are substances that deplete the Ozone layer. The use of CFCs was completely phased out by 2010. Decreases in effective stratospheric chlorine have also been measured as a result of the treaty. It was monumental because by 2009 all nations of the United Nations had signed the treaty.

The U.S. Environmental Protection Agency determined that air rated above 100 is hazardous for some or all groups. For the data shown, how many days was the air hazardous? *see graph

The air would have been hazardous for some or all groups for 3 days.

Which provides more cooling for a styrofoam cooler, one with 10 lb of ice at 0 degrees C or 10 lb of water at 0 degrees C?

The ice provides more cooling because as ice undergoes the solid to liquid phase change it absorbs heat

What are the main air pollutants presented in Sec. 2? What is the method of formation for each? How does each impact life?

The main air pollutants are: Carbon monoxide= disrupts oxygen delivery in the body and can also affect CNS. Ozone= Reduces lung function and may have cardiac effects that interfere with food production and storage in plants. Sulfur oxides= It is a respiratory irritant. Nitrogen oxides= respiratory irritants. Particulate matter, PM= can lead damage to lungs/tissue and heart attacks, Formation 3O2 = 2O3 CO2 + C = 2CO S + 2O = SO2 N2 +2O2 = 2NO2

1. Consider stratospheric ozone. What is its molecular formula? Where is it located? What units are used to quantify it? (8.1)

The molecular formula is O3. It is mostly located in the ozone layer, which is the region of the stratosphere where ozone is concentrated the most. The units used to quantify ozone are Dobson units.

When looking at an element on the periodic table,

The top number is the atomic number = #of protons/#of electrons Bottom # is the mass # = sum of the # of protons and neutrons

What are the numerical value and units for Planck's constant? Describe the model in which we use Planck's constant. How is this model useful? (8.5)

The units for Planck's constant is a joule-second, or J • s. The numerical value for this constant is 6.63 x 10^-34 J x sec It helps us with the energy and wavelength model in which we can see the relationship between these. The shorter the wavelength the higher the energy, or the longer the wavelength the lower the energy which shows an inverse relationship. The constant explains one photon of electromagnetic radiation to the frequency.

Describe the damage that UV radiation can cause in your body. Describe some precautions you can take to limit this damage. (8.7)

UV radiation can cause sunburn in the short term and skin cancer in the long term. Preventative actions include going outside less, wearing more clothes, and wearing sunscreen when in direct sunlight

Describe examples of the ecological damage caused by UV radiation. (8.7)

UV radiation from the sun has always been a factor on both humans and ecological life. UV-A wavelengths, which range from 320-400 nm, are essential to life. But once they become UV-B, they become shorter and more harmful. It can induce skin cancer in human beings and also cause snow blindness. In regards to plantlife, it hinders photosynthesis. Overexposure to UV-B will reduce the productivity, size and quality of the crops life. It also increases the chance of disease in plants/crops. Overexposure to UV-B also impaires the productivity for phytoplankton in aquatic ecosystems.

Why does a piece of metal feel cooler than a piece of wood at the same temperature?

You sense heat flowing from your body as cool, and metal is a better conductor than wood

Ozone levels drop off sharply at night. Explain why.

because there is no sunlight to provide for the reactions needed to create ozone.