Chem Exam 3

Which of the following will need to be taken into account in advancing nuclear technologies? Select all that apply.

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

Polymers that can be reshaped when heated are called _____ polymers.

Thermoplastic

Which types of radiation are emitted with no resulting change in the mass number of the isotope? Select all that apply.

Y Radiation B particles

How many protons and neutrons are found in chlorine-37?

17 protons; 20 neutrons

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

Causes thyroid cancer

One possible disadvantage of using graphite as a primary coolant in a nuclear reactor is that burning graphite can react with water to produce ______ gas, which is explosive.

H2

Why is ionizing radiation used to treat some cancers?

Ionizing radiation damages the DNA in cancer cells, which are then unable to multiply and spread.

In a molecular substance, the covalent bonds between the atoms hold the individual molecule together as a unit and may be referred to as ______ forces. The nonbonding forces of attraction between one individual molecule and another are called ______ forces.

intramolecular; intermolecular

Photovoltaic cells constructed of thin layers of alternating n- and p-type semiconductors are preferable to those with thicker layers because _____. Select all that apply.

they are more efficient due to lower internal resistance smaller quantities of silicon are needed for device construction

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

A loss of cooling water caused the nuclear plant to explode. The disaster occurred during an electric power safety test. Large quantities of radioactive material were released into the atmosphere and over the surrounding countryside. A lack of sufficient control rods contributed to the overall disaster.

Which of the following statements correctly describes the peptide bond? Select all that apply.

A peptide bond is formed between the amino group of one amino acid and the carboxyl group of another. Each amino acid can form at least two peptide bonds.

Which of the following options correctly describe a polymer? Select all that apply.

A polymer is made up of repeating units called monomers. Polymers have high molecular masses. The prefix poly indicates that a polymer is made up of many smaller units.

When a water wheel or hydroelectric dam harnesses the energy of water, the ______ energy of the water at the top of a waterfall, before the precipice, is converted to ______ energy in the wheel or turbine blades.

potential; kinetic

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

radioactivity

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

238^Pu 9^Be

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

2; 4

In a crystal of silicon, each silicon atom is bonded to ____ other silicon atoms.

4

How many neutrons are in the carbon-11 isotope?

5

Five of the "big six" polymers undergo _____ polymerization.

Addition

Which of the following statements correctly defines radioactivity?

An unstable isotope of an element spontaneously emits radiation.

Which of the following elements may be added to pure silicon to create a p-type semiconductor? Select all that apply.

Boron Gallium

Which of the following options correctly describe the risks associated with different types of electrical power plants? Select all that apply.

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.

Solar thermal energy can be harnessed by a process called _____ solar power (CSP), in which solar collectors gather a large area of sunlight into a small area. This light is converted to heat, which is used to generate electrical power.

Concentrating

Polymers that are formed by a combination of functional groups such that a small molecule (e.g., water) is eliminated are known as ______ polymers.

Condensation

Which of the following options correctly describe the components of a nuclear power plant? Select all that apply.

Cooling towers and/or a sizable body of water near the nuclear reactor are important to remove excess heat from the reactor. The primary coolant transfers the heat generated by the nuclear reactor to a steam generator. The control rods and fuel rods are contained within a reactor vessel.

What type of forces are a result of an attraction between molecules due to a distortion in the electron cloud, which causes an uneven distribution of negative charge?

Dispersion forces

The process of intentionally adding small amounts of other elements to pure silicon is called

Doping

An addition polymer is formed when two monomers containing ____ bonds react in the presence of a(n) ____ initiator.

Double; free radical

Which of the following options correctly describe the process of nuclear fission? Select all that apply.

During nuclear fission, a large nucleus splits into smaller ones. Energy is released during nuclear fission.

Which of the following are different forms of polystyrene? Select all that apply.

Expandable Crystal

Which of the following statements correctly describe polystyrene? Select all that apply.

Expandable polystyrene is light and a good thermal insulator. Crystal polystyrene is hard and brittle.

True or false: A nuclear equation is balanced in the same way as any other chemical equation.

False

True or false: A radioactive sample will be less active at a lower temperature, and radioactive waste can be safely stored by freezing it.

False

True or false: A recycled-content product must be composed entirely of one type of recycled plastic.

False

Which of the following physical properties is associated with a polymer that possesses amorphous regions?

Flexibility

Which of the following disadvantages are specifically associated with coal-based power plants but not nuclear power plants? Select all that apply.

Generation of air pollutants Ash generation

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

Half-life

Which state generates the most geothermal energy and why?

Hawaii; volcanic activity

Which of the following options correctly identify possible disadvantages of using graphite as the primary coolant in a nuclear reactor, such as those experienced at Chernobyl? Select all that apply.

Hot graphite can react with water to produce hydrogen gas, which is flammable. Graphite is a form of carbon, which can burn if the temperature is high enough.

Which statement is about the use of water to generate power is correct?

Hydroelectric dams have been used for over a century to generate electricity.

Why is pure silicon not a good electric conductor under ordinary circumstances?

In a crystal of Si the 4 outer electrons of the Si atoms are fixed in the Si-Si bonds and cannot move through the crystal.

Which of the following statements correctly describe beta emission from a radioactive isotope? Select all that apply.

In this type of radioactive decay, a neutron is converted to a proton in the nucleus. The atomic number increases by 1.

What forces cause polyethylene to be a solid material?

London dispersion forces

How does the process of nuclear fission produce energy?

Mass of the reactants is converted into energy, which is released.

Which of the following statements correctly describe proteins? Select all that apply.

Monomers are joined through condensation polymerization.20 different monomers can be combined in any ratio to form the polymer.

Which of the following options correctly describe semiconductors? Select all that apply.

Most semiconductors are made from a crystalline form of silicon. Photovoltaic cells are made from semiconductors.

Which of the following options correctly describe how a simple photovoltaic cell is assembled? Select all that apply.

Multiple layers of doped n- and p-type semiconductors are placed in close contact. 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.

Which of the following options correctly describe the fuel used in a nuclear power station? Select all that apply.

Nuclear fuel pellets are packed into fuel rods, which are bundled together. The nuclear fuel contains UO2 pellets.

Which of the following is/are considered municipal solid waste (MSW)? Select all that apply.

Old microwave Banana peel Grass clippings

Which of the following polymers are formed through addition polymerization? Select all that apply.

PP LDPE PS HDPE PVC

Which of the following options correctly describe the applications of the big six polymers? Select all that apply.

PS is used to fabricate food wrap. PP is used in the manufacture of carpeting.

The bond between one amino acid and another (shown) is called a(n) _____ bond. This type of bond is an example of the _____ functional group.

Peptide; amide

Which of the following statements correctly describe/define the word plastic? Select all that apply.

Plastic is both an adjective and a noun. Plastic is sometimes used a synonym for synthetic polymer.

Which of the following options correctly describe plasticizers? Select all that apply.

Plasticizers disrupt the regular packing of polymer molecules. PVC commonly contains plasticizers.

The backbone of both proteins and nylon are linked by the same functional group making them both _____.

Polyamides

A molecule made up of many repeating units linked together is called a(n) ____ , while the repeating units are called

Polymer; monomer

Which of the following are advantages of recycling? Select all that apply.

Recycling may contribute to lower pollution of air, water, and soil during manufacture. The amount of waste in landfills is reduced. Recycling helps us to conserve natural resources such as petroleum, timber, and water.

What is the most common monomer arrangement for PVC, PP, and PS?

Repeating head-to-tail

A(n) _____ is a material that has a limited capacity to conduct an electric current.

Semiconductors

Which of the following options correctly describe addition polymers? Select all that apply.

The formation of an addition polymer often involves a radical initiator. The monomers of addition polymers usually contain a C=C double bond

Which of the following options correctly explain how a nuclear power plant is used to generate electricity?

The heat generated by the nuclear reaction is used to generate steam, which drives a turbine to produce electrical energy.

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

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

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

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 of the following factors determine whether or not a nucleus will undergo nuclear fission? Select all that apply.

The number of protons in the nucleus The size of the nucleus

Which of the following options correctly describe how to balance a nuclear equation? Select all that apply.

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

Which of the following options correctly interpret and explain the equation E = mc2? Select all that apply.

The symbol c in this equation represents the speed of light. This equation can be used to explain how a nuclear reaction produces energy. This equation shows that matter can be converted into energy.

Which of the following factors do NOT affect the half-life of a radioisotope? Select all that apply.

The temperature of the sample The physical state of the radioactive sample The initial concentration of radioisotope present in the sample The atmospheric pressure

Which of the following statements correctly describe the half-life of a radioactive nuclide? Select all that apply.

The time taken for half the nuclei to decay is the same regardless of the initial number of nuclei present. The half-life for a given radioisotope is the same under all reaction conditions. The half-life is the time taken for the level of radioactivity in a sample to drop to half of its initial value.

Which of the following statements correctly describe true recycling? Select all that apply.

True recycling involves a closed loop where materials are collected, sorted, and converted into consumer products that are later recycled. True recycling needs to be marketed in order to have a consumer base for the products produced. True recycling requires synergy by many different people and agencies.

Which of the following options correctly describe amino acids? Select all that apply.

Twenty amino acids occur naturally. An amino acid has an amine group and a carboxylic acid functional group bonded to a carbon.

Which compound of uranium is typically used in nuclear fuel?

UO2

Which of the following options correctly describe condensation polymerization? Select all that apply.

When the monomers of a condensation polymer combine a small molecule is eliminated. Nylon is an example of a condensation polymer.

Which alternative energy source(s) has/have seen a notable increase in the amount of electricity generated in the last decade? (Select all that apply.)

Wind Solar/PV

Which of the following does NOT describe the capture of wind energy (both in the past and present) as a potential source of power?

Wind farms can be placed at any location in the world to efficiently produce energy.

An amino acid contains a(n) _____ and a(n) _____.

amine carboxylic acid

A thermoplastic polymer _____.

can be melted and reshaped with heat

Renewable energy sources are _______.

continually and rapidly replenished from natural sources

The repeating head-to-tail monomer arrangement is the most common for PVC, PP, and PS. This arrangement provides more _____ regions in the polymer.

crystalline

Polymers can possess different regions, which are characterized by the degree of order in the polymer chains. Regions of the polymer that are very ordered are called _____ regions, whereas regions of the polymer that are very disordered are called _____ regions.

crystalline; amorphous

The intermolecular forces that cause polyethylene to be a solid material are _____ forces.

dispersion

IR, visible, and ultraviolet radiation are all types of ______ radiation, whereas ______ radiation includes alpha and beta particles as well as gamma radiation.

electromagnetic; nuclear

Einstein's equation E = mc2 means that matter can be converted into:

energy

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

fission

Ethylene is the smallest member in the family of _____ containing a carbon-carbon _____ bond.

hydrocarbon; double

Dispersion forces are a type of _____ force that causes an attraction between molecules that results from a distortion of the _____ cloud that causes an uneven distribution of charge.

intermolecular; electron

A phenyl group ______. (Select all that apply.)

is composed of a 6-membered ring of carbon atoms has the formula -C6H5

Sustainable packaging ______. (Select all that apply.)

is recovered effectively after use is safe and healthy for individuals throughout its life cycle optimizes the use of renewable or recycled source materials

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

The Sun's rays hit earth every hour with enough energy to _____.

meet the world's energy demand for an entire year.

The small repeating units used to synthesize polymers are called

monomers

Waste such as leftover lasagna, old toaster ovens, and grass clippings are considered to be _____ solid waste.

municipal

Select the two types of semiconductors from the following list.

n-type p-type

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 β particle, is expelled from the nucleus.

neutron; proton; electron

The root of the word monomer means _____.

one unit

Boron and gallium doped silicon semiconductors may function as _____ semiconductors.

p-type

The term _____ is sometimes used as a synonym for synthetic polymer.

plastic

A compound that is added in small amounts to make a polymer more soft and pliable is called a(n) _____.

plasticizer

Renewable energy sources include ______. (Select all that apply.)

solar power geothermal power hydroelectric power

Covalent bonds, which govern chemical changes in molecular substances, consist of shared electron pairs. These bonds are ______ than intermolecular forces, which govern the physical changes of molecular substances.

stronger

Packaging materials designed and used in such a way to reduce their environmental impact are called _____ packaging materials.

sustainable