Test 4: 7 & 8

Which of the following options correctly describe the Chernobyl nuclear disaster?

- A lack of sufficient control rods contributed to the overall disaster - Large quantities of radioactive material were released into the atmosphere and over the surrounding countryside - The disaster occurred during an electric power safety test

Which of the following options correctly describe how a simple photovoltaic cell is assembled?

- A specific arrangement of p-n junctions ensures that electrons flow in a specific direction - The conduction of electricity is made possible by p-n junctions - Multiple layers of doped n- and p-type semiconductors are placed in close contact

Which of the following disadvantages are specifically associated with coal-based power plants but not nuclear power plants?

- Ash generation - Generation of air pollutants

Which of the following options correctly describe electrical energy produced by different types of power plants?

- Both nuclear power plants and fossil fuel plants make use of steam turbine to generate electricity - Both fossil fuel plants and nuclear power plants utilize energy released by a reaction to generate electricity - No type of power plant shows 100% efficiency in converting chemical energy to electrical energy

Which of the following options correctly compare and contrast a nuclear power station with a nuclear weapon?

- Both nuclear power plants and nuclear weapons produce energy from nuclear fission - the concentration of fissionable U-235 is much lower in the fuel used for a nuclear power plant than that used for a nuclear weapon

Which of the following effects can develop over time as a result of exposure to radiation?

- Cancerous growths - Birth defects in offspring - Mutations in genetic material

Which of the following units are measured to measure radioactivity as disintegrations per unit time?

- Curie - Becquerel

Which of the following will need to be taken into account in advancing nuclear technologies?

- More efficient transformation of energy - Methods for dealing with nuclear waste - Developing materials that can operate at higher temperatures

Which of the following options correctly describe how nuclear waste is handled at nuclear power stations in the US?

- Most reactor waste in the US is stored at the site where it was generated - spend nuclear fuel rods are stored temporarily in deep basins of water

Which of the following options correctly describe the risks associated with different types of electrical power plants?

- Nuclear power plants do not produce any greenhouse gases directly - Both nuclear power plants and coal-based plants represent a significant danger to mine workers - Coal-based power plants produce large quantities of greenhouse gases

Which of the following statements correctly describe how nuclear radiation interacts with matter?

- Nuclear radiation causes the formation of free radicals from matter - Radioactive emissions cause electrons to be dislodged from an atom or molecule - All types of nuclear radiation cause the ionization of matter

Which of the following options correctly describe the processes occurring at the anode of a galvanic cell?

- Oxidation takes place at the anode - The anode is the source of electrons

Which of the following are common sources of significant background radiation?

- Radiation from food sources - Radiation from rocks and soil - Cosmic radiation

which of the following options correctly describe sources of background radiation?

- Rocks and soil contain uranium, which is a source of background radiation - Radioactive elements may be present in food and water - Radon is the major source of natural background radiation on Earth

Which of the following options correctly describe sources of background radiation?

- Rocks and soil contain uranium, which is a source of background radiation - Radioactive elements may be present in food and water - radon is the major source of natural background radiation on Earth

Which of the following options correctly describe a half-reaction?

- Shows the electrons lost by the reactants in a galvanic cell - The overall process occurring in a galvanic cell includes both an oxidation and a reduction reaction. the two parts are each known as half-reactions - Shows the electrons gained by the reactants in a galvanic cell

Which of the following options correctly describe spent nuclear fuel?

- Spent nuclear fuel contains many different radioactive isotopes - Spent nuclear fuel is classified as high-level radioactive waste

In the absence of reprocessing, which of the following options are feasible for the storage of high-level radioactive waste?

- Storage in geological repositories deep underground - Storage in steel or concrete vaults that must be monitored constantly

Which of the following statements correctly describe the changes that occur when a nucleus emits alpha particles?

- The atomic number decreases by 2 - The nucleus emits 2 protons and 2 neutrons

Which of the following options correctly describe the cathode in a galvanic cell?

- The cathode receives electrons from the anode - Reduction occurs at the cathode

Which of the following options correctly describe a modern lead-acid automobile battery?

- The electrolyte in a lead-acid battery is H2SO4 - 12-V lead-acid batteries are made up of six cells that each generate 12-V - The anode and the cathode are both solids (Pb and PbO2)

Which of the following were (and are) among the consequences of the Chernobyl nuclear disaster?

- The incident resulted in immediate fatalities - People in the area experienced radiation sickness - There has been an increased incidence of various forms of cancer in the area

Which of the following options correctly describe environmental consequences that result from the production of batteries?

- The mining of metal ores needed to produce batteries leaves mine tailings and other waste that must be cleaned up - Lead-acid batteries may leak and release corrosive material into the environment

Which of the following options correctly describe the factors that influence the ability of a nucleus to undergo fission?

- The number of protons and neutrons influence the ability of a nucleus to undergo fission - Heavy nuclei may undergo fission if bombarded with high-energy neutrons - Small nuclei are less likely to undergo fission

Which is the more destructive species, OH- or .OH? Why?

- The radical .OH - Free radicals are very reactive and will react with any other molecules present

Which of the following factors determine whether or not a nucleus will undergo nuclear fission?

- The size of the nucleus - The mass of the nucleus (# of protons and neutrons = mass) - The number of protons in the nucleus

Which of the following options correctly describe how to balance a nuclear equation?

- The sum of the subscripts on the left of the equation must equal the sum of the subscripts on the right - The sum of the mass numbers on the left of the equation must equal the sum of the mass numbers on the right

Which of the following options correctly describe the term 'current'?

- The unit of current is the ampere - current is the rate of electron flow in a cell

Which of the following options correctly describe the nuclear incident at Three Mile Island in Pennsylvania in 1979?

- There were no fatalities during this incident - This incident involved a loss of coolant from the reactor - There was a partial meltdown at the Three Mile Island reactor

An aqueous solution of ___ acid is often used as the primary coolant in nuclear reactors. This solution absorbs heat and also acts as a(n) ___ by slowing down neutrons.

- boric - moderator

What is true about radioactivity?

- damages DNA - damages WBC - used to treat certain cancers

Ionizing radiation interacts with matter to produce ___.

- electrons - radicals - ions

Which of the following were among orders issued to US nuclear power plants by the NRC following the Fukushima disaster?

- improve venting systems to protect against a backup of steam - have sufficient equipment to deal with problems in all reactors simultaneously - install equipment to monitor water levels in spent fuel pools

Which of the following options correctly describe semiconductors?

- most are made from crystalline form of silicon - photovoltaic cells are made from semiconductors - acid rain is produced as a result of SO2 release during the metal ore refining process

Which of the following options correctly describe how neutrons are generated from a neutron source such as poo-bee?

-- ^9Be reacts with alpha particles to produce neutrons -- The name "poo-bee" indicates that the neutron source contains plutonium and beryllium -- A heavy radioactive element such as plutonium decays to release 2^4He particles

Which of the following options correctly describe the relationships between the Group IA metals?

--Na and K are more abundant than Li in the Earth's curst --Li, Na, and K are highly reactive metals --Li is lighter than Na

Place the steps involved in producing electricity from nuclear power in the correct order, starting with the first step at the top.

1. Heat is generated by nuclear reactions in a reactor vessel 2. Heat is transferred to the primary coolant 3. The primary coolant transfers heat to a steam generator 4. A steam turbine transfers energy to an electrical generator

Place the following steps in the nuclear fuel cycle in the correct order, starting with the first step at the top of the list.

1. Mining of uranium ores 2. conversion of U3O8 to UF6 3. Uranium enrichment 4. fuel fabrication and use 5. storage of spent fuel

Place the steps involved in the gaseous diffusion method producing enriched uranium in the correct order, starting with the first step at the top.

1. Uranium ore is converted to UF4. 2. Gaseous UF4 is reacted with F2 gas to give UF6. 3. Uranium-containing compounds are passed through a series of permeable membranes 4. Compounds containing the lighter^235U isotope diffuse more rapidly, allowing separation

Place the physiological effects of a single radiation does in order of severity, starting with the effects of the highest does at the top.

1. hemorrhaging, ulcers 2. nausea, vomiting 3. lesions 4. slight decrease in WBC count

When a nucleus emits an alpha particle, the atomic number decreases by ___ and the mass number decreases by ___.

2, 4

Approximately how much of the electric power produced in the US is generated by nuclear power stations?

20%

Approximately what percentage of the electrical energy generated in the united States is produced from nuclear energy?

20%

If you have 200.0 g of radioisotope with a half-life of 5 days, how much isotope would remain after 15 days?

25.0 g

Which of the following equations represents a reduction half-reaction?

2H+ + 2e- --> H2

The half-life of radium-226 is 1.60x10^3 yr. How much time must pass before a 2.50-g sample decays to a point where only 0.156 g of the isotope remains?

6400 years

Weapons-grade uranium is approximately...

90% U-235

The average level of radiation that is constantly present in the natural environment at a particular location is called ___ radiation.

Background

A nuclear reactor that can produce more fissionable fuel than it consumes is called a ___ reactor.

Breeder

Which of the following balanced equations correctly shows how hydrogen gas can be generated from methane?

CH4 (g) + 2H2O (g) + heat --> 4H2 (g) + CO2 (g)

A reaction that is self-sustaining because one of the reaction products becomes a reactant is called a(n) ___ reaction.

Chain

One of the worst nuclear power plant accidents occurred at ___ in 1986.

Chernobyl

The amount of fissionable nuclear fuel required to sustain a nuclear chain reaction is called a ___ mass.

Critical

In the famous equation E=mc^2, the symbol represents

E = energy m = mass c = speed of light

What was the primary cause of the meltdown at the Fukushima Daiichi nuclear plant in Japan in 2011?

Earthquake and tsunami

The flow of electrons through an external circuit produces ___, which is the flow of electrons from one region to another driven by a difference in ___ energy.

Electricity, potential

A(n) ___ cell is a type of electrochemical cell in which electrical energy is converted to chemical energy.

Electrolytic

T/F: A nuclear equation is balanced in the same way as any other chemical equation

False:

T/F: a radioactive sample will be less active at a lower temperature, and radioactive waste can be safely stored by freezing it.

False: The half-life of a radioisotope, and therefore the rate at which it decays, is independent of temperature

The time taken for half the radioactive nuclei in a sample to decay is called the ___ of the radioisotope.

Half-life

Which of these locations would be best suited to geothermal energy as a source to operate homes?

Hawaii

H2 gas can be stored using metal ___ such as LiH, which absorb H2 molecules into the spaces within their crystal structure.

Hydrides

What is the major disadvantage of burning hydrogen as a source of energy?

Hydrogen is extremely flammable and can explode when mixed directly with oxygen

Depleted uranium...

Is mostly, but not all U-238

What is the specific danger associated with the radioactive isotope iodine-131?

It causes thyroid cancer

Which of the following types of storage facilities are currently used for long-term storage of nuclear waste in the US?

Nuclear waste is enclosed in concrete vaults on-site at the nuclear reactor where it is generated. -- Water basins are used for temporary storage of spent fuel rods

The spontaneous emission of nuclear radiation (particles and/or energy) from an unstable nucleus is called ___.

Radioactivity

Which of the following pollutants may be released into the environment during the production or incorrect disposal of batteries?

SO2 Toxic metals -- Cd, Pb, and Hg are all toxic metals that may be released into the environment if batteries are disposed incorrectly CO2 -- the mining of ores is energy intensive and results in the burning of significant quantities of fossil fuels

Fission is the process of creating energy by

Splitting large nuclei to form smaller, more stable nuclei

Which of the following fission products released from the Chernobyl reactor is dangerous because it concentrates in bones?

Sr-90

Why is plutonium-239 considered an international security problem?

The ^239Pu produced in nuclear power reactors could be incorporated into nuclear weapons

What is the role of the secondary coolant in a nuclear power plant?

The secondary coolant is converted to steam, which runs the steam turbine to generate electricity

Which is the role of the secondary coolant in a nuclear power plant?

The secondary coolant is converted to steam, which runs the steam turbine to generate electricity

T/F: The electrical energy generated by a nuclear power station is no different from the electrical energy produced by a fossil fuel plant.

True

Which compound of uranium is typically used in nuclear fuel?

UO2

What is enriched uranium?

Uranium containing a higher percentage of ^235U than would be present in naturally occurring uranium

Which of the following sites was designated in 197 as a long-term storage facility for high-level radioactive waste in the US?

Yucca Mountain

Both nuclear power plants and nuclear weapons use fuel containing the fissionable isotope ___.

^235U

Which two elements are commonly used as a source of neutrons in nuclear reactors?

^238Pu ^9Be

Which of the following naturally occurring radioactive isotopes are commonly found in the human body?

^40K ^14C

Chemical energy is converted directly into electrical energy in...

a galvanic cell

Which of these is not a realistic risk associated with nuclear power plants?

a nuclear explosion

The "doping" of a semiconductor to improve its performance means

adding small amounts of other elements to the pure semiconductor to change the freedom of electron motion throughout the crystal

What type of radiation is given off in this nuclear reaction? (210/84)Po --> (206/82) Pb + ___

alpha

At present, it will be difficult and perhaps inappropriate to develop an economy based on burning hydrogen rather than natural gas or gasoline because

although hydrogen is abundant, pure hydrogen is not found naturally on earth. Hydrogen is difficult or expensive to isolate and collect

Sievert

an international unit equal to 100 rem

In any electrochemical cell oxidation occurs at the ___.

anode

A major advantage of a fuel cell over a standard battery is that

as long as oxygen and fuel are supplied, a fuel cell will not "run down" like a battery will

alpha emission

atomic number decreases by 2

beta emission

atomic number increases by 1

gamma radiation

atomic number remains unchanged

Batteries must be used in addition to solar cells when generating household electricity because

batteries must store and then supply the energy when sunlight is not available

As fuel cells become more widely accepted and are used more, we will

be able to generate electricity in places where we cannot now do so

How do the interactions that are broken in water when it is boiled compared with those broken when water is electrolyzed?

boiling water breaks intermolecular attractions and electrolysis breaks covalent bonds

Radiation can be used to treat certain types of cancer because ___.

cancer cells divid rapidly and are therefore susceptible to radiation damage.

Smokestacks at these plants release sulfur oxides and carbon dioxide into the air

coal-burning plants

Radioactive isotopes tend to achieve stability by a sequence of steps called a radioactive ___ series.

decay

Einstein's equation E = mc^2 means that no matter can be converted into

energy.

Curie

equivalent to the activity of 1 g of radium

The process during which a large nucleus is split into smaller ones is called nuclear ___.

fission

Reduction

gain of electrons

A(n) ___ cell converts energy released spontaneous chemical reaction into electrical energy.

galvanic

In general, a modern hybrid vehicle is less polluting than a standard vehicle because it runs on both a

gasoline engine and an electric motor urn by a rechargeable battery

A(n) ___ is a type of chemical equation that shows the electrons either lost or gained by the reactants

half-reaction

gamma ray

high-energy photon, with no charge or mass

permanent isolation from the biosphere is required for

high-level radioactive waste

beta particle

high-speed electron emitted from the nucleus

electromagnetic radiation

includes all the different types of light

nuclear radiation

includes alpha and beta particles as well as gamma radiation

Which is not a benefit associated with nuclear power plants?

inexpensive to operate

Nuclear radiation and electromagnetic radiation that can remove electrons from atoms and molecules are collectively known as ___ radiation.

ionizing

Semiconductors, such as the element silicon, may be used in cells that convert solar radiation to electricity. One of the major difficulties encountered in using silicon is that it

is expensive to produce large quantities of extremely pure silicon

low-level radioactive waste includes

laboratory clothing contaminated with radioisotopes

Oxidation

loss of electrons

there are significantly lower hazards associated with

low-level radioactive waste

During nuclear fission, the mass of the products is slightly ___ than the mass of the reactants. This mass difference accounts for the energy ___ by the reaction.

lower, released

How does the process of nuclear fission produce energy?

matter is converted into energy, which is released

The greatest percentage of background radiation comes from

naturally occurring radon

During beta emission, a(n) ___ is converted into a(n) ___ in the nucleus of the atom. During this process a high-energy ___, also called a beta particle, is expelled from the nucleus.

neutron, proton, electron

The control rods in a nuclear reactor contain substances such as boron or cadmium, which are able to absorb ___.

neutrons: absorbing neutrons allows the control rods to regulate or stop the chain reaction.

The Prius, a hybrid car produced by Toyota, uses a battery that its maker claims should not have to be recharged or replaced during the lifetime of the car. The type of battery used in the Prius is

nickel-metal hydride

For safety reasons, high-level nuclear waste (HLW) must be contained

permanently

Alpha particle

positively charged; consists of 2 protons and 2 neutrons

Stable isotopes differ from radioactive isotopes in their neutron to ___ ratio

proton

Radiation causes the greatest damage to ___.

rapidly dividing cells

Electrolysis is a process that

requires an electrical current to decompose water into hydrogen gas and oxygen gas

Most high-level nuclear waste in the United States is currently

sealed at the sites where it was produced

Which factor will support the growth of nuclear energy in the future?

smaller, more efficient reactor design

Which is not considered to be low-level radioactive waste?

spend fuel rods

High-level radioactive waste includes

spent nuclear fuel

Which is a common characteristic of both nuclear and conventional electric power plants?

steam turbines

Rem

takes into account the damage caused to human tissue

Rad

the absorption of 0.01 J of radiant energy per kilogram of tissue

What condition must be met for a battery to be rechargeable?

the electrochemical reaction of the battery must be reversible

What is the primary determinant of the voltage developed by a battery?

the nature of the materials in the reaction

Which does not contribute to your annual radiation does?

the number of hours you spend listening to the radio

Depleted uranium produced in uranium enrichment is ___.

uranium consisting almost entirely of U-238

Which type of widely used battery is not rechargeable?

zinc-manganese alkaline