NAME:
Ch 25 Nuclear Chemistry
Period:
STUDY GUIDE
/68
Matching
Match each item with the correct statement below.
A. positron
D. radioactivity
B. alpha particle
E. gamma radiation
C. beta particle
F. transmutation
____
____
____
____
____
____
1.
2.
3.
4.
5.
6.
spontaneous emission from the nucleus of an atom
emitted helium nucleus
energetic electron from decomposed neutron
high-energy photons emitted by a radioisotope
particle of charge +1 and mass equal to that of an electron
conversion of an atom of one element to an atom of another element
Match each item with the correct statement below.
A. fission
E. scintillation counter
B. fusion
F. neutron absorption
C. Geiger counter
G. neutron moderation
D. radioisotope
____
____
____
____
____
____
____
7.
8.
9.
10.
11.
12.
13.
atom with unstable nucleus
combination of two nuclei to form a nucleus of greater mass
process that decreases the number of slow-moving neutrons
splitting of nucleus into smaller fragments
process that slows down neutrons so a reactor fuel can capture them to continue a chain reaction
radiation detector that makes use of a phosphor-coated surface
radiation detector that makes use of a gas-filled metal tube
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 14. Which of the following is one way that nuclear reactions differ from chemical reactions?
A. Atoms are not involved in nuclear reactions.
B. Nuclear reactions are not affected by temperature.
C. Nuclear reactions are slowed by increasing pressure.
D. Nuclear reactions do not occur in a predictable manner.
____ 15. What is the final product of a sequence of spontaneous nuclear decay reactions?
A. a stable isotope
C. a hydrogen atom
B. a radioisotope
D. a more massive atom
____ 16. The charge on a gamma ray is ____.
A. +2
B. 1
C. 0
D. 2
____ 17. What particle is emitted in alpha radiation?
A. electron
C. helium nucleus
B. photon
D. hydrogen nucleus
____ 18. Which of the following is the same as a beta particle?
A. photon
C. helium nucleus
B. electron
D. hydrogen nucleus
____ 19. What is the change in atomic mass when an atom emits a beta particle?
A. Mass decreases by 2.
C. Mass does not change.
B. Mass decreases by 1.
D. Mass increases by 1.
____ 20. What is the change in atomic mass when an atom emits gamma radiation?
A. Mass decreases by 2.
C. Mass remains the same.
B. Mass decreases by 1.
D. Mass increases by 1.
____ 21. The least penetrating form of radiation is ____.
A. beta radiation
B. gamma radiation C. alpha radiation
D. X rays
____ 22. Ionizing radiation that identical to helium nuclei is ____.
A. X radiation
B. gamma radiation C. beta radiation
D. alpha radiation
____ 23. What is the change in the atomic number when an atom emits an alpha particle?
A. decreases by 4
B. decreases by 2
C. increases by 1
D. increases by 2
____ 24. What is the change in atomic number when an atom emits a beta particle?
A. decreases by 4
B. decreases by 2
C. increases by 2
D. increases by 1
____ 25. What type of radiation is likely to occur when the ratio of protons to neutrons is below the band of stability?
A. alpha decay
C. neutron emission
B. beta decay
D. positron emission
____ 26. Which symbol is used for an alpha particle?
A. He
B. He
C. He
D. He
____ 27. How does a positron differ from an electron?
A. A positron has no electrical charge, unlike an electron.
B. A positron has a charge opposite that of an electron.
C. A positron has less mass than an electron.
D. A positron has greater mass than an electron.
____ 28. What particle decomposes to produce the electron of beta radiation?
A. proton
B. neutron
C. electron
D. positron
____ 29. A nitrogen isotope decays by positron emission. What element is the product of the decay?
A. helium
B. carbon
C. nitrogen
D. oxygen
____ 30. What particle completes this transmutation equation?
B+
He
N+
?
A. alpha particle
B. beta particle
C. neutron
D. proton
____ 31. What product of fission is necessary in order to establish a chain reaction?
A. alpha particle
C. two or more protons
B. two or more neutrons
D. gamma rays
____ 32. A neutron breaks down to form ____.
A. an alpha particle
C. a proton and an electron
B. two protons
D. a helium nucleus
____ 33. Which of the following reasons is why spent fuel rods are stored in a pool of water?
A. Water recovers useful energy from the continuing reaction.
____ 34.
____ 35.
____ 36.
____ 37.
B. Water increases the speed of the chain reaction in the fuel rods.
C. Water acts as a radiation shield to reduce the radiation levels.
D. Water dissolves the nuclear waste in the rods so it is easier to handle.
How long do spent fuel rods remain dangerously radioactive?
A. The rods are no longer radioactive because the radioisotopes are used up.
B. Spent fuel rods remain radioactive for several years after the fuel is exhausted.
C. It takes tens of thousands of years for the radioisotopes in the rods to decay to safe
levels.
D. It is impossible to determine how long it will take for the radioisotopes to decay because
they last too long.
What is the main product of the fusion reactions in our sun?
A. hydrogen-2
B. hydrogen-3
C. helium-3
D. helium-4
Which of the following occurs when an isotope decays by the process of beta emission?
A. The mass number changes.
B. The atomic number changes.
C. Protons are released from the nucleus.
D. The number of neutrons remains unchanged.
What particle is needed to complete this nuclear reaction?
Rn
Po + ____
A. He
B.
C. H
D. n
e
____ 38. When radium-226 (atomic number 88) decays by emitting an alpha particle, it becomes ____.
A. polonium-222
B. polonium-224
C. radium-222
D. radon-222
____ 39. How does an atom with too many neutrons relative to protons undergo radioactive decay?
A. by emitting an alpha particle
C. by emitting gamma radiation
B. by emitting a beta particle
D. by emitting X radiation
____ 40. What particle does argon-39 (atomic number 18) emit when it decays to potassium-39 (atomic number 19)?
A. neutron
B. electron
C. proton
D. alpha particle
____ 41. What is the product of this radioactive decay?
Mn
____ + e
A.
B.
C.
D.
Co
Mn
Fe
Cr
____ 42. What particle is needed to complete the following equation?
N + ____
C+ H
A. n
B.
C. He
e
D.
e
____ 43. To what element does polonium-208 (atomic number 84) decay when it emits an alpha particle?
A.
B.
C.
D.
Pb
Po
Pb
Rn
____ 44. What is the approximate half-life of uranium-238?
A. hundreds of years
C. millions of years
B. thousands of years
D. billions of years
____ 45. Which of the following naturally occurring radioisotopes would be most useful in dating objects thought to
be millions of years old?
A. carbon-14; t
C. thorium-234; t
= 25 days
= 5.73
10 years
B. potassium-40; t
= 1.28
10 years
D. radon-222; t
= 3.8 days
____ 46. A transmutation reaction must always involve a(n) ____.
A. change in the number of electrons in the atom
B. decrease in the number of neutrons in the nucleus of an atom
C. increase in the number of neutrons in the nucleus of an atom
D. change in the number of protons in a nucleus of an atom
____ 47. How does the radiation from radioisotopes cause damage to human tissue?
A. by ionization knocking electrons away from atoms
B. by breaking the bonds between atoms in molecules
C. by causing nuclear chain reactions inside cells
D. by causing transmutations of atoms within cells
____ 48. Which particles maintain a nuclear chain reaction?
A. neutrons
C. high-energy electrons
B. radioactive products
D. alpha particles
____ 49. Which statement correctly applies to controlled nuclear chain reactions?
A. They take place in nuclear reactors.
B. They are always fusion reactions.
C. They produce no radioactive by-products.
D. They are characteristic of atomic bombs.
____ 50. Which of the following materials is commonly used to remove heat from a nuclear reactor core?
A. compressed air
C. chlorofluorocarbons
B. liquid sodium
D. mercury
____ 51. A reaction in which small nuclei combine to form a heavier nucleus is a ____.
A. fission reaction
C. background reaction
B. chemical reaction
D. fusion reaction
____ 52. Which statement applies to nuclear fusion?
A. It takes place in the sun.
C. It can be controlled in the laboratory.
B. It occurs at low temperatures.
D. It is used in medicine.
____ 53. A reaction that results in the combining of smaller atomic nuclei is ____.
A. chemical
B. fission
C. fusion
D. ionization
____ 54. What does neutron absorption accomplish in a nuclear reactor?
A. It slows down the reaction.
C. It increases the rate of heat absorption.
B. It speeds up the reaction.
D. It recycles the fuel.
____ 55. Which element is used in control rods to absorb neutrons in a nuclear power plant?
A. carbon
B. sodium
C. plutonium
D. cadmium
____ 56. What substances are used as neutron moderators in a nuclear reactor?
A. carbon and water
C. plutonium and neptunium
B. liquid sodium and water
D. cadmium or other metal
____ 57. Which of the following statements is correct?
A. Water can be used to slow down neutrons in a nuclear reactor.
B. Carbon control rods absorb neutrons in a nuclear fission reaction.
C. Energy must be added to a nuclear reactor to initiate a chain reaction.
D. The product of nuclear reactions is safe because the radioisotope is used up.
____ 58. How are radioactive isotopes used to diagnose thyroid problems?
A. Production of radioactive iodine by the thyroid is measured.
B. Uptake of radioactive iodine by the thyroid gland is measured.
C. Destruction of damaged cells by radioisotopes is measured.
____ 59.
____ 60.
____ 61.
____ 62.
____ 63.
D. Absorption of gamma rays from ingested radioisotopes is measured.
What instrument is used routinely to check a person's exposure to radiation over a period of time?
A. Geiger counter
C. film badge
B. scintillation counter
D. tracer
What is the main detector of a Geiger counter?
A. ionizable gas in a metal tube
C. plates of ionizable plastic
B. phosphor-covered surface
D. potassium metal surface
What is the main detector of a scintillation counter?
A. ionizable gas in a metal tube
C. plates of ionizable plastic
B. phosphor-covered surface
D. potassium metal surface
How are radioisotopes used in radiation therapy for cancer?
A. to detect unusual cells
C. to kill fast-growing cells
B. to strengthen normal cells
D. to change cancer cells to normal cells
Why should a radioactive tracer used to detect diseases in internal organs emit beta particles or gamma
rays?
A. Alpha radiation is too damaging to be used internally.
B. Beta particles and gamma rays do not interact with biological molecules.
C. Beta particles and gamma rays are absorbed faster by damaged cells.
D. Alpha particles cannot travel through several meters of body tissue.
Numeric Response
64.
65.
number 20?
How many neutrons are in an alpha particle?
What is the approximate ratio of neutrons to protons for stable atoms below atomic
66.
The half-life of radon-222 is about four days. After how many days is the amount of
radon-222 equal to one-sixteenth of its original amount?
67.
Above which atomic number are all nuclei radioactive?
68.
Above which atomic number are the Transuranium elements located