26) What type of radioactive decay produces a daughter nuclide that is the same element as the
parent nuclide?
A) alpha
B) beta
C) gamma
D) positron
E) none of the above
27) How does the emission of a gamma particle effect the radioactive atom?
A) The atom has a lower amount of energy.
B) The atomic number decreases.
C) The atomic mass increases.
D) The atom gains energy for further radioactive particle emission.
E) All of the above are true.
28) What is the main product when Bk emits a gamma ray?
A) Bk
B) Am
C) Cm
D) Cf
E) none of the above
16
29) Which statement about positron emission is FALSE?
A) occurs when a proton is converted into a neutron and a positron
B) symbol is: e
C) occurs with alpha and beta decay
D) alternative symbol is β+
E) All of the above are true.
30) What happens to the atomic number of a nucleus that emits a positron?
A) It remains the same.
B) It increases by one.
C) It decreases by one.
D) It increases by two.
E) It decreases by two.
31) What happens to the mass number of a nucleus that emits a positron?
A) It remains the same.
B) It increases by one.
C) It decreases by one.
D) It increases by two.
E) It decreases by two.
32) The emitted particle with the mass of an electron but carrying a 1+ charge is named the:
A) proton.
B) proelectron.
C) positron.
D) plusion.
E) none of the above
33) Which of the following types of radiation has the highest penetrating power?
A) alpha particles
B) beta particles
C) gamma rays
D) positrons
E) none of the above
34) Which of the following is NOT a type of radioactive emission?
A) alpha rays
B) beta rays
C) gamma rays
D) positrons
E) All of the above are types of radioactive emissions.
35) Radon-219 decays to radon-218 by releasing:
A) e.
B) gamma rays.
C) n.
D) e.
E) none of the above
36) Which type of particle can be emitted by an unstable nucleus?
A) He
B) e
C) e
D) all of the above
E) none of the above
37) A Geiger-Muller counter detects radioactivity by:
A) developing film which is exposed by radioactive particles.
B) emission of light from a NaI crystal when radioactivity passes through the crystal.
C) ionization of argon gas in a chamber which produces an electrical signal.
D) analyzing the mass and velocity of each particle.
E) none of the above
38) A scintillation counter detects radioactivity by:
A) developing film which is exposed by radioactive particles.
B) emission of light from a NaI crystal when radioactivity passes through the crystal.
C) ionization of argon gas in a chamber which produces an electrical signal.
D) analyzing the mass and velocity of each particle.
E) none of the above
39) Beyond which element in the periodic table (based on atomic number) are the successive
elemental nuclei considered to be radioactive?
A) Uranium
B) Radium
C) Barium
D) Bismuth
E) Lead
40) Which of the following statements regarding radiation are FALSE?
A) Radioactivity is a natural part of our environment.
B) All elements heavier than bismuth are radioactive.
C) All radioactive elements are spontaneously decaying towards formation of a stable element.
D) The time for half of the original sample to spontaneously decay is called the half-life
E) All of the above are true.
41) The rate of spontaneous nuclear decay:
A) can be increased by increasing the temperature.
B) can be increased by increasing the concentration of the radioactive element.
C) is independent of concentration or temperature.
D) can be increased by addition of a nuclear catalyst.
E) all of the above
42) If the half-life of a radioactive isotope is 32 days, how many half-lives must pass before a
sample is less than ?
A) 2
B) 5
C) 7
D) 9
E) More information is needed.
43) Iodine-131 has a half-life of 8 days. How much of a 1000 milligram sample of iodine-131
would be left after 32 days?
A) 500 milligram
B) 250 milligram
C) 125 milligram
D) 62.5 milligram
E) 31.25 milligram
44) Tritium ( H ) is an isotope of hydrogen that is sometimes used to make the hands of
watches glow in the dark. The half-life of tritium is 12.3 years. After 49 years, approximately
how much of the original tritium remains?
A) 50%
B) 25%
C) 12.5%
D) 6.25%
E) 3.12%
45) The radioactive gas radon:
A) is a product of the radioactive decay series of uranium.
B) is the single greatest source of human radiation exposure.
C) is more hazardous for smokers than nonsmokers.
D) all of the above
E) none of the above
46) Which fact about carbon-14 dating is FALSE?
A) C-14 is formed by neutron bombardment of nitrogen in the upper atmosphere.
B) C-14 dating can only work on items that come from a living source.
C) C-14 dating only works as far back as 50,000 years.
D) C-14 accuracy is verified by dating antique items of a known age.
E) All of the above statements are true.
47) If an object has 6.25% of the C-14 activity as a living organism, the age of the
item is:
A) 11,460 years.
B) 17,190 years.
C) 22,920 years.
D) 28,650 years.
E) More information is needed.
48) If an object has 25% of the C-14 activity as a living organism, the age of the
item is:
A) 11,460 years.
B) 17,190 years.
C) 22,920 years.
D) 28,650 years.
E) More information is needed.
49) If an object is 28,650 yrs old, how many C-14 half-lives have occurred as
compared to a living organism?
A) 6 half-lives
B) 5 half -lives
C) 4 half-lives
D) 3 half-lives
E) More information is needed.
50) If an object is 17,190 yrs old, how many C-14 half-lives have occurred as
compared to a living organism?
A) 6 half-lives
B) 5 half-lives
C) 4 half-lives
D) 3 half-lives
E) More information is needed.
51) The first person to artificially cause a nucleus to undergo a fission reaction was:
A) Otto Hahn.
B) Lise Meitner.
C) Fritz Strassman.
D) Enrico Fermi.
E) all of the above
52) The self-amplifying reaction in which neutrons produced by the fission of one nucleus would
induce fission in other nuclei is called:
A) critical mass.
B) chain reaction.
C) nuclear fusion.
D) positron emission.
E) none of the above
53) Why can U-235 produce a chain reaction?
A) Extremely high amounts of energy are released in the reaction.
B) Neutrons produce the fission reaction and are also a product of the reaction.
C) All elements above bismuth (#83) can undergo fission based chain reactions.
D) Chain reactions merely need sufficient mass (critical mass) to start.
E) All of the above are true.
54) Which of the following statements about the creation of the nuclear bomb is FALSE?
A) Einstein lobbied President Roosevelt to pursue creation of the bomb.
B) American war intelligence feared the Germans were ahead of the Allies in developing nuclear
weapons in WWII.
C) J.R. Oppenheimer headed the Manhattan Project.
D) The Germans were defeated by the time the bomb had been developed.
E) All of the above are true.
55) Nuclear power:
A) generates 20% of the electricity needed in the U.S.
B) generates heat which boils water and turns a steam turbine to produce electricity.
C) generates no air pollution or greenhouse gases.
D) uses almost no fuel compared to fossil fuel plants.
E) All of the above are true.
56) The control rods of a nuclear reactor:
A) regulate the chain reaction because they contain catalysts.
B) regulate the chain reaction because they absorb the U-235 atoms.
C) regulate the chain reaction because they absorb the neutrons.
D) regulate the chain reaction because they produce positrons.
E) none of the above
57) Nuclear power is criticized because:
A) of long term storage issues of radioactive wastes.
B) it is an expensive form of energy.
C) it is not as efficient as burning fossil fuels.
D) of the danger of detonation into a nuclear bomb.
E) all of the above
58) Nuclear fusion:
A) is the formation of heavier elements from lighter ones.
B) releases a larger amount of heat than nuclear fission.
C) is the energy source of the sun and stars.
D) produces non-radioactive elements.
E) all of the above
59) Nuclear fusion:
A) requires intense temperatures that make it impossible to harness as an energy source with our
current technology.
B) is the basis of the hydrogen bomb.
C) can be done but requires the detonation of a traditional fission bomb.
D) is a possible energy source of the future.
E) all of the above
60) Which of the following is NOT a unit used for expressing radioactivity:
A) roentgen
B) geiger
C) rem
D) curie
E) All of the above are units used to express radioactivity.
61) Acute radiation damage:
A) results from lower doses of radiation over extended periods of time.
B) results from exposure to lower amounts of radiation in a short period of time.
C) can result in death.
D) results in an increased chance of cancer.
E) all of the above
62) Isotope scanning involves:
A) radioactive isotopes that are used in place of x-rays.
B) radioactive isotopes that are absorbed by specific organs.
C) destroying cancerous cells by intense radiation levels.
D) acute radiation exposure.
E) none of the above
63) What symptoms can be experienced from exposure to dangerous levels of radiation?
A) decreased white blood cell count
B) skin burns
C) hair loss
D) vomiting
E) all of the above
64) Radiation therapy involves:
A) radioactive isotopes that are used in place of x-rays.
B) radioactive isotopes that are absorbed by specific organs.
C) destroying cancerous cells by intense radiation levels.
D) acute radiation exposure.
E) none of the above.
17.3 Algorithmic Questions
1) When Th undergoes alpha decay, what is the atomic mass of the element that is produced?
A) 88
B) 228
C) 236
D) 92
E) none of the above
2) Suppose a Po daughter nuclide was obtained after the alpha decay of a parent nuclide. The
symbol of the original parent element is:
A) Po
B) Pb
C) Ra
D) Rn
E) none of the above
3) When Ac undergoes beta decay, what is the atomic number of the element that is
produced?
A) 87
B) 90
C) 88
D) 91
E) none of the above
4) When Ac undergoes positron emission, what is the atomic number of the element that is
produced?
A) 87
B) 90
C) 88
D) 91
E) none of the above
5) A 1.2 kg sample of Th-228 has a half-life of 1.9 years. How many grams of Th is left after 5.7
years?
A) 150
B) 75
C) 300
D) 0
E) none of the above
6) A 3.6 mole sample of Co-60 has a half-life of 5.2 years. How many moles of Co is left after
A) 0.056
B) 0.11
C) 0.23
D) 0
E) none of the above
7) A C-14 dating experiment revealed that an artifact had 50.0% of the activity of a modern
organism. Given the half-life of C-14 is 5730 years, approximately how old is the artifact?
A) 28,650
B) 34,380
C) 22,920
D) 5,730
E) none of the above
17.4 Essay Questions
1) Briefly describe the main features of the three types of radiation: alpha, beta, and gamma.
Also explain what happens to the nucleus of an atom when it is exposed to each of these.
2) Briefly distinguish between nuclear fission and nuclear fusion.