Chemistry Unit Test

Which radioisotope is used as a tracer in nuclear scanning? carbon -14 uranium-238 technetium-99m iodine-129

What happens during beta decay? A photon is ejected from a nucleus. A helium-4 nucleus is ejected from a nucleus. A neutron changes into a proton, or a proton changes into a neutron. A proton changes into an electron, or an electron changes into a proton.

Consider the incomplete equation below If this equation was completed, which statement would it best support? Nuclear fusion produces elements that are heavier than helium. Nuclear fusion produces elements that are lighter than helium. Nuclear fission produces elements that are heavier than helium. Nuclear fission produces elements that are lighter than helium.

Which best describes a chain reaction associated with a nuclear reaction? Neutrons released during a fusion reaction cause other nuclei to fuse. Neutrons released during a fission reaction cause other nuclei to split. Helium nuclei released during a fission reaction cause other nuclei to split. Helium nuclei released during a fusion reaction cause other nuclei to fuse.

What is transmutation? the end product of radioactive decay one type of radioactive decay the steps that make up a decay series the conversion of one element into another

A target is shielded from a radioactive sample by a sheet of metal. What kind of radiation can pass through the sheet of metal and hit the target? gamma rays only gamma rays and beta particles beta particles only beta particles and alpha particles

An isotope undergoes radioactive decay by emitting radiation that has no mass. What other characteristic does the radiation have? some shielding required positive or negative charge low penetrating power no charge

A sample contains 16.75 g of the radioisotope U-236 and 50.25 g of its daughter isotope, Th-232. How long did it take for decay to take place if one half-life of U-236 is 23 million years? 46 million years 69 million years 92 million years 115 million years

What part of an atom is involved in a chemical reaction? proton neutron nucleus electron

An article about half-lives describes a daughter isotope. What is a daughter isotope? the isotope that forms from the radioactive decay of a less stable isotope the isotope that forms from the radioactive decay of a more stable isotope an isotope that undergoes radioactive decay to form a less stable isotope an isotope that undergoes radioactive decay to form a more stable isotope

How do scientists perform artificial transmutations? They bombard nuclei with high energy particles. They use electricity to initiate the decay chain sequence. They use extreme heat to initiate the decay chain sequence. They bombard larger molecules with atoms.

A fusion reaction takes place between carbon and another element. Neutrons are released, and a different element is formed. The different element is lighter than helium. heavier than helium. the same weight as helium. dependent on the element that reacted with carbon.

Uranium-232 has a half-life of 68.8 years. After 344.0 years, how much uranium-232 will remain from a 100.0-g sample? 1.56 g 3.13 g 5.00 g 20.0 g

Which type of reaction does this diagram represent? nuclear fission because an atom is splitting into two fragments nuclear fusion because the products that are produced are radioactive nuclear fission because a large amount of energy is being released nuclear fusion because atomic nuclei combine to form a heavier nucleus

Consider the following decay series.Which of the first four radioisotopes in the decay series has the longest half-life? Pa-234 Th-234 U-234 U-238

Examine the nuclear reaction: . Why is this classified as a nuclear reaction rather than a chemical reaction? It is not balanced. A new compound is formed. A change has occurred in a nucleus. A new element has been formed.

An atom that has 84 protons and 86 neutrons undergoes a reaction. At the end of the reaction, it has 82 protons and 84 neutrons. What happened to the atom? It accepted radiation in a chemical reaction. It donated neutrons to another atom in a chemical reaction. It emitted an alpha particle in a nuclear reaction. It accepted protons in a nuclear reaction.

How does an equation for an artificial transmutation differ from the equation for a radioactive decay? The mass numbers are balanced. The atomic numbers are balanced. Two products are shown. Two reactants are shown.

Leutium-176 has a half-life of 3.85 1010 years. After 1.155 1011 years, how much leutium-176 will remain from an original 16.8-g sample? 2.10 g 3.00 g 5.56 g 8.40 g

A radioisotope forms a stable isotope after it undergoes radioactive decay. Which is the best conclusion to draw from this statement? It undergoes alpha decay. It undergoes beta decay. It does not participate in a decay series. It does not have a long half-life.

Sodium-24 has a half-life of 15 hours. After 45 hours, how much sodium-24 will remain of an original 50.0-g sample? 5.56 g 6.25 g 16.7 g 25.0 g

Which statement is true about nuclear fusion? It is caused by the same process that causes nuclear fission. It does not occur naturally in the solar system. It has very low activation energy. It produces nearly all the elements that are heavier than helium.

Which element is nuclear fusion least likely to produce? hydrogen, which has an approximate mass of 1 chlorine, which has an approximate mass of 35 argon, which has an approximate mass of 39 silicon, which has an approximate mass of 28

Consider the image of a fossil below. How is half-life most likely used with respect to this fossil? to find the mass of the fossil to find the age of the fossil to determine the species shown by the fossil to determine if radiation is being emitted from the fossil

Both nuclear fusion and nuclear fission reactions release radioactive waste. involve the splitting of atoms. are utilized in nuclear power plants. release large amounts of energy.