Energy Final

Energy Ranks

1. X-rays 2. Ultraviolet 3.Visible 4.Infrared

ENERGY CONVERSION: If your monthly energy bill is for 400 kWh, then how many megajoules (MJ) is that? Remember that 1 kWh = 3600 kJ.

400kWh x 3600kJ = 1440000kJ/1000 = 1440MJ Correct: 1440 MJ

KINETIC AND POTENTIAL SCALING: If a ball's speed is raised from 8m/s to 64m/s, then its potential energy is how many times larger?

8 x 8 = 64 (multiply initial speed by a number that gives you the final speed) Correct: 8 times larger

A correct radioactive decay process is

Bromine (Z=35) radioactively decays to Selenium (Z=34) by β+ (positron emission) decay. Radon (Z=86) radioactively decays to Polonium (Z=84) by α decay. Xenon (Z=54) radioactively decays to Iodine (Z=53) by β+ (positron emission) decay

Choose the correct gas for each question below.

CH4: Which greenhouse gas is produced by manure or decomposing waste in landfills? N2O: Which gas is 300 times more effective per unit weight as a greenhouse gas than CO2? CO2: Which greenhouse gas had a concentration of 280 ppm prior to the industrial revolution and has increased to 380 ppm today?

A correct ranking of countries from highest to lowest for hydroelectric capacity is

China, U.S or Brazil, Canada, India or Japan

Choose the correct statement concerning bioethanol.

Correct The two countries producing 90% of the world's ethanol are the U.S. and Brazil Correct: The important chemical functional group in ethanol is -OH. Incorrect Second generation bioethanol comes from algae. Incorrect The important chemical functional group in ethanol is -COOH. true: First generation bioethanol comes from food plants such as corn, sugarcane, and sugarbeets. true: The two countries producing 90% of the world's ethanol are Brazil and the U.S. true: The steps for bioethanol production are: cellulose production, sugar production, and then fermentation. false: Cellulose easily separates into sugar molecules at room temperature. true: During fermentation, sugars are converted into ethanol and carbon dioxide by yeast.

Choose the correct statement regarding which major gas components comprised the atmosphere of the "young" Earth or the Earth today.

Correct: "Young" Earth = CO2 and N2 Correct: Earth Today = N2 and O2

kWh Cost: If a 4200 Watt oven is on for 7 hours and the power company charges $ 0.10 per kilowatt-hour (kWh), then how much did it cost to run the oven?

Correct: $2.94

How much sulfur is emitted by a 0.6 GW power plant burning oil for 12 h? Assume that oil emits 1800 kg sulfur per GWh.

Correct: 12960 kg

A heat engine operates between 35 C and 270 C. If this engine extracts a total energy of 300 MJ from fuel, then how many MJ of energy could be used as useful mechanical energy?

Correct: 130. MJ

What is the total R value for a wall made of 4 inches of wood, 3 inches of fiberglass, and 3 inches of foam? Assume that the R values for a 1-inch thickness of these materials is given by: R(1" wood) = 2, R(1" fiberglass) = 4, and R(1" foam) = 5.

Correct: 35

CALCULATING KINETIC ENERGY: If a 1600-kg vehicle travels at 10 m/s (or approximately 22 mph), then find its kinetic energy in kilojoules (kJ).

Correct: 80 kj

A pot of water on the stove has a temperature increase of 45 C. How much is that temperature increase in degrees Fahrenheit?

Correct: 81 degrees F increase

Which statement is true about greenhouse gases?

Correct: CH4 is more effective per unit weight as a greenhouse gas than CO2 but less effective than N2O Correct: CO2 had a concentration of 280 ppm prior to the industrial revolution and has increased to 400 ppm today Correct: CH4 is produced by manure or decomposing waste in landfills Correct: Manure or decomposing waste in landfills is the primary contributor to methane in the atmosphere. Correct: CO2 is produced by the combustion of fossil fuels Correct: CO2 has had the largest concentration increase over the last 100 years Correct: N2O is 300 times more effective per unit weight as a greenhouse gas than CO2 Correct: H2O is responsible for about 60% of the greenhouse effect Correct: N2O is produced by bacteria in soil using nitrogen-rich fertilizer

Choose the correct statement related to the production of bioethanol.

Correct: Cellulose is composed of glucose (or sugar) molecules. Correct: During fermentation, sugars are converted into ethanol and carbon dioxide by yeast. Correct: Enzymes and/or heat are required to separate cellulose into sugar molecules

Which statement is correct about fossil fuels?

Correct: Coal can have different chemical compositions depending on where it is mined.

Which statement is true about a nuclear reactor?

Correct: Removing the control rods from the reactor speeds up fission. Correct: Inserting the control rods into the reactor slows down fission. Correct: Sudden Loss of primary coolant water in the pressurized water reactor slows down fission. Correct: Adding the moderator to the reactor speeds up fission. Correct: Removing the control rods from the reactor speeds up fission.

A correct ordering from lowest to highest pH is:

Correct: Soda pop, coffee, blood, soap Correct: Soda pop, coffee, milk, soap Correct: Soda pop, milk, blood, soap Correct: Coffee, milk, blood, soap

Choose the correct statement concerning comparisons of biofuels.

Correct: Sugarcane ethanol has a lower wholesale price compared to corn ethanol. true: Corn ethanol has a higher crop land requirement than sugarcane ethanol. true: Enzymes and/or heat are required to separate cellulose into sugar molecules. Correct: The energy gain for sugarcane ethanol is larger than for corn ethanol. true: Corn ethanol has a higher wholesale price compared to sugarcane ethanol. true: Algae biodiesel has a lower crop land requirement than sugarcane ethanol.

Choose the correct statement about cities and their relative latitudes and/or annual average solar intensity.

Correct: The annual average solar intensity of Richmond is higher than Detroit. Correct:The annual average solar intensity of Denver is higher than Richmond. Correct: The annual average solar intensity of Richmond is lower than Phoenix. Correct: The annual average solar intensity of Phoenix is higher than Denver Correct: The latitude of Denver is higher than Richmond.The latitude of Phoenix is lower than Richmond. Correct: The annual average solar intensity of Denver is higher than Detroit.The latitude of Detroit is higher than Phoenix.

Which of the following statements about power generation for the electric grid is true?

Correct: Virginia has a higher percentage of nuclear power generation than California. Correct: The state with the highest percentage of nuclear power generation is Vermont. Correct: California has a higher percentage of gas power generation than Virginia.

Choose the correct statement concerning reducing/oxidizing agents or the reaction of Zn and Cu.

Correct: When Zn metal reacts with Cu2+ ions, Zn metal is the reducing agent. Correct: Zinc is a stronger reducing agent than copper Correct: Lithium is a stronger reducing agent than copper. Correct: Lithium is a stronger reducing agent than zinc Correct: When Zn metal reacts with Cu2+ ions, Zn metal is the reducing agent Correct: When Zn metal reacts with Cu2+ ions, the Cu2+ ions are the oxidizing agent.

A correct ranking of fuels from highest to lowest energy content is:

Correct: natural gas, gasoline, coal

If the Earth's temperature increases, then the CO2 feedback cycle causes:

Correct: the CO2 concentration to decrease due to more rock weathering, thereby counteracting the temperature increase.

Decide whether each of the following statements regarding the Earth is true or false.

False: The major element comprising the solid inner core of the Earth is lead. False: The Earth is approximately 4.6 trillion years old. False: The Earth does not have a magnetic field and is therefore unprotected from solar particle radiation. False: The circumference of the Earth is approximately 40,000 miles. True: The Earth has a magnetic field that protects it from solar particle radiation. True: The major element comprising the solid inner core of the Earth is iron. False: The circumference of the Earth is approximately 6,400 km. False: The major element comprising the solid inner core of the Earth is uranium.

Choose the correct statement concerning radiation that is ionizing or non-ionizing

Gamma Rays are ionizing radiation. Alpha Particles are ionizing radiation. Beta Particles are ionizing radiation.X-Rays are ionizing radiation. Visible Light are non-ionizing radiation Radio Waves are non-ionizing radiation Infrared light are non-ionizing radiation Microwaves are non-ionizing radiation

Choose the correct statement concerning the fundamental particles of electrons, protons, and neutrons.

Incorrect The proton is a particle found outside the nucleus. Correct: The electron is a particle found outside the nucleus. Incorrect The charged particles that move in wires to create electric current are protons. Incorrect A proton is attracted to another proton. Incorrect An electron is repelled by a proton.

Choose the correct statement concerning a girl skateboarding on a U-shaped track

Incorrect When the girl skates from the top of the track down to the bottom, her kinetic energy decreases. Correct: When the girl skates from the top of the track down to the bottom, her kinetic energy increases. Incorrect When the girl skates from the top of the track down to the bottom, her potential energy increases. Incorrect When the girl skates from the bottom of the track back up to the top, her kinetic energy increases. Incorrect When the girl skates from the bottom of the track back up to the top, her potential energy decreases.

Choose the correct ranking from largest to smallest for energy sources or consumption in the U.S.

Sources for ELECTRICITY Generation: Natural Gas, Coal, Nuclear Sources for TOTAL Energy: Oil, Natural Gas, Coal, Nuclear Power, Hydroelectric Sources for major SECTORS: Transportation, Industrial, Residential, Commercial

Choose the correct statement concerning photosynthesis or respiration.

Sugar is consumed in respiration. Sugar is produced in photosynthesis. O2 is consumed in respiration. O2 is produced in photosynthesis. H2O is consumed in photosynthesis. CO2 and H2O are consumed in photosynthesis. CO2 and H2O are produced in respiration.

A sample of water vapor at 110 C is cooled to 90 C. Which of the following statements is true regarding this process?

The correct order of steps is: cooling of water vapor, condensation of water vapor, and then cooling of liquid water The condensation of water vapor has the highest energy change The cooling of water vapor has the lowest energy change The cooling of liquid has neither the highest or lowest energy change The overall process is exothermic

Which statement below about atmospheric layers is correct?

The troposphere is the atmospheric layer where weather primarily occurs

Which one of the following statements is true for assimilation?

The uptake of ammonia, ammonium, nitrate and nitrite by plants to be used in the formation of plant and animal proteins

Choose the correct statement regarding the behavior of water.

The water phase with the smallest temperature increase when adding 10 kcal of heat is liquid water A water molecule is polar with a negative oxygen end + a positiv hydrogen end The water phase with the highest heat capacity is liquid water Ice has a lower density than liquid water, therefore it floats

Greenhouses Sunlight + Gases

UVC = 100 - 280nm UVB = 280 - 315nm UVA= 315 - 400nm Visible to the human eye = 400nm (violet) - 750nm ( red ) Infrared = 750nm (red) and longer Gas Ranking: H2O, CO2, CH4

Choose the type of heat transfer for each of the following examples. Note that answers may be used multiple times or not at all.

convection: The smoke from a fire is drafted up the chimney of your fireplace. convection: When hot air rises to higher altitudes. conduction: When you burn your tongue on hot soup. CONVECTION - Heat is transmitted through a substance (difference in temp); Motion CONDUCTION - Movement within fluid by hotter and lens dense rise and colder materials to sink; Contact RADIATION - Emission/Transmission of energy in the form of waves; Rays

Indicate whether each of the following statements is true or false.

false: Global annual CO2 emissions have increased by approximately 30 Mt from the year 1800 to today. false: Global CO2 concentrations have increased by approximately 10 ppm from the year 1800 to today. false: The CO2 concentration today is approximately 4,000 ppm and is increasing at 150 to 200 ppm per decade. false: The change in CO2 concentration during each of the last several glacial cycles was approximately 100 ppb.

Determine whether each of the statements about ozone is true or false.

false: Ozone is a molecule with four oxygen atoms. true: Tropospheric ozone is more prevalent in the northern vs. southern hemisphere. false: Ozone is formed from the reaction of carbon dioxide with sunlight.

Determine whether each statement about particulate matter pollution is true or false.

false: PM-10 is made of toxic organic molecules, sulfates, and/or metals. false: Particulate matter around 10 millimeters in size is designated PM-10. false: PM-10 travels further in the air than PM-2.5. true: Around 20,000 to 50,000 Americans die each year due to PM pollution.

Determine whether the listed process or processes increase or decrease CO2 in the atmosphere.

increase CO2: burning of forests increase CO2: volcanic action increase CO2: volcanic action and burning of forests

Indicate whether each of the following statements is true or false.

true: In a coal-fired power plant, thermal energy is converted into mechanical energy. true: The molecules in cold air move slower than in hot air. false: Approximately 30% percent of original energy in the coal is lost to heat in a coal-fired power plant.

Determine whether each statement concerning different wavelengths of light is true or false.

true: Light with a wavelength of 100 nm is in the ultraviolet region. true: Light with a wavelength of 100 nm is completely absorbed by the atmosphere. true: Light with a wavelength of 750 nm has the color of red.

Determine whether each of the following statements about sulfur oxide and/or nitrogen oxide pollution is true or false.

true: Nitrogen in the air is the primaray source of nitrogen oxide polution. false: The largest source of nitrogen oxide pollution is industrial activities. false: A car's catalytic converter removes nitrogen oxide pollution and is most efficient at room temperature.

Indicate whether each of the following statements about water is true or false.

true: The ice-to-liquid phase change of water requires less energy than the liquid-to-vapor phase change. true: The heat capacity of liquid water is greater than the heat capacity of gas vapor. true: Ice has a lower density than liquid water and therefore floats.

Choose whether the given unit is a unit of power or a unit of energy.

unit of energy: kilocalorie (kcal) unit of energy: watt x year (Wyr) (costs about $1) unit of power: gigawatt (GW)

(1) Indicate the correct order for the steps given below in the greenhouse effect. (2) Rank the types of greenhouse gases from those that contribute the most to the greenhouse effect down to the least.

(1) 1: The sun emits visible radiation 2: Visible radiation passes through the Earth's atmosphere 3: Greenhouse gases absorb and emit infrared radiation 4: Greenhouse gases absorb and emit infrared radiation (2) 1: water vapor 2: carbon dioxide (CO2) 3: methane ( CH4) 4: nitrogen (N2) and oxygen (O2)

MATH REQUIRED PROBLEM: (1) Water is heated and its temperature is increased: If 2 kg of water is heated from 20 ° C to 60 ° C, then what is the heat added in kcal (same as food calories)? (2) If you heated 2.5 kg of water using 75 kcal of energy, then what would be the temperature increase of the water (degrees C)?

(1) 80 kcal (2) 30 degrees C

A correct definition for a power unit is:

(KW) Kilowatts: 103 -- 1,000 (MW) Megawatts: 106 -- 1,000,000 (GW) Gigawatts: 109 -- 1,000,000,000 (TW) Terawatts: 1012 -- 1,000,000,000,000

A correct ordering from lowest to highest boiling point for molecules found in crude oil is:

(lowest to highest number of carbon atoms) Correct: C8 H18, C16 H34, C20 H42, C31 H64

KINETIC AND POTENTIAL SCALING: If a ball's speed increases from 16 m/s to 32 m/s, then its kinetic energy is how many times larger?

16 x 2 = 32 2 x 2 = 4 (multiply initial speed by a # that gives you final speed. Multiply # by itself) Correct: 4 times larger

Rank the following fuels from HIGHEST to LOWEST energy content.

1: natural gas (methane) 2: gasoline 3: coal 4:ethanol

Choose the correct statement about the electric grid

Correct: Electric vehicles will increase demand on the grid, where the new plug-in hybrid Chevy Volt has a smaller Li ion battery to charge compared to the Nissan Leaf electric car. Correct: Electric vehicles will increase demand on the grid, where the new Nissan Leaf electric car has a larger Li ion battery to charge compared to the plug-in hybrid Chevy Volt. Correct: High voltage, low current transmission lines are used in the grid to minimize resistive heating losses. Correct: Supply and demand of power on the grid must be matched in real time because the energy cannot be stored. Correct: The highest voltage used on the U.S. electric grid is 1,000 kV. Correct: One method to decrease peak demand on the grid is to charge higher rates during times of high demand.

Choose the correct statement concerning electrical circuits.

Correct: Electrons in a wire move from the negative to the positive battery terminal Correct: A standard alkaline battery (AAA, AA, C, D) has a voltage of 1.5 V. Correct: In a light bulb circuit, when the battery voltage is increased the bulb's brightness increases. Correct: In a circuit, when the resistance is increased the current decreases

Which statement is true about breaking or forming bonds?

Correct: Energy is released when forming bonds between C, H, and O atoms to make coal. Correct: Energy is required to break bonds between C, H, and O atoms to make coal.

A correct ordering from lowest to highest cost for types of power plants is:

Correct: Fuel Costs (low to high): Wind, Nuclear, Coal Correct: Capital Investment Costs (low to high): Coal, Nuclear, Wind

A correct ranking of gases from those that contribute the most to the greenhouse effect down to the least is:

Correct: H2O, CO2, N2

Which statement is correct about Hydraulic Fracture?

Correct: Hydraulic Fracture wells include horizontally drilling Correct: In the last forty years, U.S. Oil production has decreased. Correct: Hydraulic fracture is exempt from the Clean Water act. Correct: Hydraulic Fracture are used to extract natural gas Correct: In the last forty years, U.S. Natural gas production has increased Correct: Hydraulic Fracture wells are pumped with a mixture water, sand, and additives Correct: Hydraulic fracture breaks up shale rock to release Hydrocarbons

Choose the correct statement about hydrogen and/or hydrogen fuel cells.

Correct: Hydrogen has a higher energy density per unit mass compared to gasoline Correct: When hydrogen reacts with oxygen in a fuel cell, oxygen takes electrons from hydrogen Correct: Hydrogen gas is not easily found in nature and must be produced using energy sources Correct: Hydrogen gas can be produced by the electrolysis of water using a battery just over 2 volts.

Choose the correct statement regarding the behavior of water.

Correct: Ice is less dense than liquid water.

Which statement below related to energy policy is true?

Correct: If a greenhouse gas policy is implemented, then the probability that the global mean temperature will increase by 5F or higher by the year 2100 is less than 25%. Correct: If a carbon tax is implemented, then the percentage cost increase of electricity generation from coal will be higher than from natural gas Correct: If no greenhouse gas policy is implemented, then the probability that the global mean temperature will increase by 5F or higher by the year 2100 is close to 100% Correct: The cost of electricity generation from least to most expensive is: coal, nuclear, solar Correct: The cost of electricity generation from least to most expensive is: coal, wind, solar

Which statement correctly states the number of neutrons in the given nucleus?

Correct: If the mass of a hydrogen nucleus (Z = 1) is 3 amu, then it has 2 neutrons. Correct If the mass of a lithium nucleus (Z = 3) is 7 amu, then it has 3 neutrons. Correct If the mass of a hydrogen nucleus (Z = 1) is 3 amu, then it has 2 neutrons. Correct If the mass of a beryllium nucleus (Z = 4) is 7 amu, then it has 3 neutrons.

Which statement is true about an increase or decrease in pH?

Correct: If the pH of a sample increases from 5 to 8, then the acid concentration decreases by a factor of 1000.

Choose the correct statement regarding the radioactive decay of the given element.

Correct: If uranium (Z = 92) undergoes β- decay, then Z = 93 for the daughter particle. Correct:If uranium (Z = 92) undergoes α decay, then Z = 90 for the daughter particle. Correct: If iodine (Z = 53) undergoes α decay, then Z = 51 for the daughter particle. Correct: If plutonium (Z = 94) undergoes α decay, then Z = 92 for the daughter particle.

Which statement about batteries is true?

Correct: In a lithium battery, Li metal is the reducing agent Correct: In an alkaline battery, Zn metal is the reducing agent Correct: In an alkaline battery, MnO2 is the oxidizing agent Correct: The cell potential for a lithium battery is higher than for a zinc battery

A correct ranking of oil spills from HIGHEST to LOWEST in terms of oil tonnage spilled is:

Correct: Lakeview Gusher, Deep Water Horizon, Exxon Valdez

Choose the correct statement concerning pollution due to the combustion of fossil fuels.

Correct: Most sulfur oxides formed during combustion come from sulfur in the fuel. Correct: Most nitrogen oxides formed during combustion come from nitrogen in the air.

Which statement is correct about oil or oil (tar) sands?

Correct: Oil takes millions of years to form. Correct: Oil sands contain sand, water, and bitumen Correct: The viscosity of bitumen is about 100,000 times greater than the viscosity of water. Correct: The viscosity of bitumen is similar to the viscosity of peanut butter.

Choose the correct statement concerning CO2 emissions or concentrations.

Correct: Over the last 200 years, CO2 concentrations have increased by approximately 100 ppm. Correct: The CO2 concentration today is approximately 400 ppm and is increasing at 15 to 20 ppm per decade. Correct: Global annual CO2 emissions have increased by approximately 30 Gt from the year 1800 to today. Correct: CO2 is responsible for about one quarter of the greenhouse effect Correct: Global CO2 concentrations have increased by approximately 100 pm from the year 1800 to today. Correct: The change in CO2 concentration during each of the last several glacial cycles was approximately 100 ppm

Choose the correct statement concerning units of power or energy

Energy: Kilowatt x hour (kWh)(Costs about $0.10) Joule(J) Calorie (Cal) Power: Megawatt(MW) Kilowatt x hr/year (kWh/yr) Calories per day (cal/day) Joule/sec

Choose the correct statement about forces

Correct: The attractive strong nuclear force keeps the protons tightly bound together in the nucleus. Incorrect An extremely weak attractive gravitational force keeps the protons tightly bound together in the nucleus. Correct: A repulsive electrostatic force causes alpha particles to scatter from a positive nucleus. Correct:A repulsive electrostatic force acts between protons in the nucleus. Correct: The attractive strong nuclear force keeps the protons tightly bound together in the nucleus. Correct:The attractive strong nuclear force acts between nucleons (i.e., protons & neutrons) in the nucleus.

Choose the correct statement regarding hydroelectric power generation.

Correct: The largest hydroelectric plant in the U.S. is the Grand Coulee dam. Correct:The power capacity of Hoover dam is approximately 2 GW. Correct:When the height difference for the falling water through a dam is doubled, then the power output is two times larger.

Which statement concerning the number of protons in the given nucleus is true?

Correct: The largest stable nucleus (lead) has 82 protons. The most stable nucleus (iron) has 26 protons. The fissile nucleus uranium-235 has 92 protons. The largest stable nucleus (lead) has 82 protons. An alpha particle has two protons.

Which statement is true about nuclear fission or bombs?

Correct: The minimum amount of fissile material that will sustain a chain reaction is called the critical mass. Correct: The isotope of hydrogen having a proton plus a neutron is called deuterium. Correct: The nuclear bomb dropped on Nagasaki in WWII was called Fat Man. Correct:The nuclear bomb in WWII that used 239Pu and an implosion-type design was called Fat Man. Correct:The nuclear bomb in WWII that used 235U and a gun-type design was called Little Boy. Correct: A moderator slows down neutrons to make fission more likely.

Choose the correct statement about the identification of a fossil fuel molecule.

Correct: The molecule corresponding to natural gas (methane) is CH4. Correct: The molecule corresponding to asphalt is C35H72. Correct: The molecule corresponding to gasoline is C8H18. Correct: The molecule corresponding to diesel is C12H26.

Which statement is true about the atom or its components?

Correct: The neutron is composed of two down quarks and one up quark. Correct: When an atom loses an electron, it is still the same element. Correct: The proton is composed of two up quarks and one down quark. Correct: The atom is 10,000 times larger than the nucleus. Correct: Isotopes have the same number of protons, but different numbers of neutrons

Choose the correct statement concerning the stability of the nucleus

Correct: The number of neutrons and protons is about equal in smaller nuclei. Correct: The number of neutrons is greater than the number of protons in larger nuclei. Correct: The number of neutrons and protons is about equal in smaller nuclei. Correct: Very small nuclei can undergo fusion and become more stable. Correct:Very large nuclei can undergo fission and become more stable. Correct:The largest stable nucleus has 82 protons. Correct: The largest stable nucleus is lead.

Choose the most appropriate power for the situation

Correct: The power consumption per capita in the U.S. is 10 kW. Correct: The power consumption of a person to survive ("caveman") is 100W. Correct: The total power consumption of the world is about 15 TW. Correct: The power output of a nuclear power plant is about 1 GW. Correct: The total U.S. power consumption 3 TW.

Choose the correct statement concerning biomass or biofuels

Correct: The two most common biofuels are ethanol and biodiesel. Incorrect Biodiesel and octane are the two most common biofuels. true: For every kg of CO2 produced, ethanol produces about the same energy (MJ/kg fuel) as octane. true: The percentage of total energy worldwide from biomass (wood, etc.) is about 4%. true: The percentage of total energy worldwide from biofuels is less than 1%.

Which statement is true about particulate matter pollution?

Correct: There are from 20,000 to 50,000 deaths/yr in the U.S. due to PM pollution Correct: PM-12.5 and PM-10 are not visible to the unaided eye Correct: Particulate matter around 10 micrometers in size is designated PM-10. Correct: PM-2.5 travels further in the air than PM-10 Correct: PM-2.5 penetrates more deeply into your lungs than PM-10 Correct: PM-2.5 is made of toxic organic molecules, sulfates, and/or metals Correct: PM-10 is made of dirt, dust, mold, and/or pollen Correct: Pm-2.5 and PM-10 are 2.5 microns and 10 microns in size respectively.

A correct ranking from highest to lowest for energy losses in an automobile is:

Correct: Thermodynamic losses of a heat engine; Frictional losses in the engine; Braking resistance

Choose the correct statement below about the chemical reaction for combining hydrogen and oxygen gas to make water: 2H2 + O2 --> 2H2O + 572 kJ.

Correct: This reaction is exothermic Correct: Breaking the H2 and O2 bonds requires energy, and forming the OH bonds in water releases energy Correct: The H2 bond and O2 bond are weaker than the OH bonds in water.

The correct ranking of countries from highest to lowest for either their total nuclear power generation or for their percentage of electrical power from nuclear is

Correct: Total nuclear power generation: U.S., France, China, South Korea

Choose the correct statement about ozone.

Correct: Tropospheric ozone is more prevalent in the northern vs. southern hemisphere.

Which statement is true about rain or acid rain?

Correct: Unpolluted rain water is acidic Correct: Sulfur oxides and nitrogen oxides in the troposphere cause acid rain Correct: There is more acid rain in the Eastern vs. Western United States. Correct: The acid rain problem is better today than in the mid-1990's.

Which statement about energy usage or energy conservation is true?

Correct: Using recycled aluminum scrap to make new aluminum cans uses 95% less energy than making aluminum cans from the raw material of bauxite ore. Correct: Using a ton of recycled paper saves 17 trees and uses 50% less water Correct: In a typical U.S. home, the energy usage for home heating & cooling is higher than for lighting & appliances Correct: To provide lighting in a room, using a compact fluorescent bulb is more energy efficient than using an incandescent bulb Correct: In a typical U.S. home, the energy usage during a year to run a refrigerator is comparable to keeping a 100-W lightbulb continuously on Correct: To heat a cup of water, using the microwave is more energy efficient than using an electric stove.

Which statement about electrons or holes at a p-n junction is true?

Correct:Electrons cannot move in a full valence band.A p-type semiconductor has missing electrons (or holes) in the lower energy valence band. Correct: Electrons can move in a partially filled conduction or valence band. Correct: An n-type semiconductor has free electrons in the upper energy conduction band. Correct: After a photon "kicks" an electron into the upper conduction band, the electron moves to the n-type side of the p-n junction. Correct: After a photon "kicks" an electron out of the valence band and leaves behind a hole, the hole moves to the p-type side of the p-n junction.

Choose the true statement below concerning wind energy?

Correct:If a wind farm has a power capacity of 150 MW, then it could generate power for a town with about 50,000 homes (assume 3 kW/home). Correct: In 2016, the state of Texas had the highest wind power capacity of any state in the U.S. Correct: In 2016, U.S. electricity generation from wind was about 67% of the amount from renewable energy sources other than hydroelectric (e.g., wind, biomass, geothermal, and solar). Correct: In 2016, U.S. electricity generation from renewable energy sources (e.g., hydroelectric, wind, biomass, geothermal, and solar) was about 15% of the total amount.

Which statement is true about the motion of surface winds in the Northern hemisphere?

Correct:In the cell between 0 and 30 degrees, surface winds flow southward and are deflected westward due to the Coriolis force. Correct: Surface winds flowing northward are deflected eastward, because they are traveling from a faster to slower speed region on Earth. Correct: Surface winds flowing southward are deflected westward, because they are traveling from a slower to faster speed region on Earth. Correct: Surface winds travel faster closer to the equator. Correct: Surface winds travel slower closer to the North pole

Choose the correct statement regarding photovoltaic cells or panels

Correct:The thickness of a CdTe thin film in a solar cell is about 2% the thickness of a sheet of paper. Correct: CdTe solar panels are becoming more popular because they are cheaper than Si solar panels. Correct: The efficiency of the best CdTe solar cells is less than 20%. Correct: CdTe has a bandgap energy of 1.5 eV, which is in the infrared portion of the EM spectrum.

Which statement is true about seasons on Earth?

During the winter in Richmond, the angle of the sun at noon from the vertical is 61 degrees (= Richmond's latitude of 37.5 degrees plus Earth's tilt of 23.5 degrees)During the spring or fall equinox in the northern hemisphere, the North pole is not tilted either toward or away from the sun.During the winter in the northern hemisphere, the North pole is tilted away the sun, making the sun appear lower in the sky.During the summer in Richmond, the angle of the sun at noon from the vertical is 14 degrees (= Richmond's latitude of 37.5 degrees minus Earth's tilt of 23.5 degrees)During the spring or fall equinox in Richmond, the angle of the sun at noon from the vertical is 37.5 degrees (= Richmond's latitude)