Practice Questions - Nuclear

1. Why are there relatively few naturally occuring radioisotopes on Earth?
(A) Radioisotopes can only be produced by synthetic reactions.
(B) Most radioisotopes originally on Earth have now decayed to stable isotopes.
(C) All radioisotopes have half-lives on the order of only a few days or years.
(D) There are naturally occuring radioisotpes but detection is difficult.

2. Large-scale use of transuranium metallic elements for construction purposes is unlikely because such elements
(A) emit radiation.
(B) are not found in nature and must therefore be synthesized via nuclear reactions.
(C) are unstable; over time they decay to form other elements.
(D) emit radiation, are not found in nature, and are unstable.

3. If 87.5 percent of a sample of pure ¹³¹I decays in 24 days, what is the half-life of ¹³¹I?
(A) 6 days
(B) 8 days
(C) 12 days
(D) 14 days
(E) 21 days

4. Which of the following is a correct interpretation of the results of Rutherford's experiments in which gold atoms were bombarded with alpha particles?
(A) Atoms have equal numbers of positive and negative charges.
(B) Electrons in atoms are agganged in shells.
(C) Neutrons are at the center of an atom.
(D) Neutrons and protrons in atoms have nearly equal mass.
(E) The positive charge of an atom is concentrated in a small region.

5. Atoms of different phosphorus isotopes
(A) react differently with other atoms.
(B) have different atomic numbers.
(C) have different numbers of protons.
(D) have different numbers of neutrons.

5. The half-life of plutonium-239 is 24,300 years. If a nuclear bomb released 8 kilograms of this isotope, how many years would pass before the amount was reduced to 1 kilogram?
(A) 12,150 years
(B) 24,300 years
(C) 48,600 years
(D) 72,900 years

6. A sodium atom has a mass number of 23. How many electrons does it have if it is not an ion?
(A) 34
(B) 11
(C) 22
(D) 23
(E) 12

7. Which is not a true statement about nuclear radiation?
(A) A vacuum will serve as an effective barrier to nuclear radiation.
(B) Intensity of nuclear radiation decreases with increasing distance from the source.
(C) Gamma rays are the most penetrating and alpha rays the least penetrating forms of radiation.
(D) Nuclear radiation can both cause cancer and be used to treat cancer.

8. Which form of energy has not yet been harnessed to generate electricity?
(A) nuclear fission
(B) water flowing downstream
(C) combustion of fossil fuels
(D) nuclear fusion
(E) solar energy

9. Which process theoretically yields the greatest energy per mole of fuel?
(A) burning natural gas
(B) burning coal
(C) fission of uranium-235
(D) fusion of hydrogen

10. Cathode rays are now known to be the same as
(A) X rays
(B) visible light
(C) electrons
(D) alpha particles

11. What did Marie Curie do that no other woman ever did?
(A) Glow like a watch dial
(B) With a devastating curve ball, led the 1969 Mets to a World Series championship.
(C) Win the Nobel Prize twice, first for Physics in 1903, and then Chemistry in 1911.

12. Which statement below is FALSE?
(A) energy is released when large nuclei split into smaller ones
(B) fusion occurs when small nuclei merge into larger ones
(C) Beta particles are the same thing as electrons
(D) An alpha particle is the same thing as a He nucleus.
(E) Gamma radiation is composed of neutrons

13. Which statement is correct for the symbol ¹⁴C?
(A) It represents the isotope of carbon with 8 neutrons.
(B) It represents the isotope of carbon with a mass number of 12.
(C) It represents the isoptope of carbon which contains 14 protons.
(D) It represents the most common form of carbon.

14. If an element has an atomic number of 10 and an atomic mass number of 20, which statement is true? A particular isotope of this element must have
(A) a relative mass of greater than 20.
(B) 10 protons per atom.
(C) ions that are neutral or have no charge.
(D) atoms whose nuclei each contain 10 electrons.

15. The half-life of radium-226 is 1620 years. What fraction of an original sample of radium-226 will remain after 4860 years have passed?
(A) one-half
(B) one-fourth
(C) one-eighth
(D) one-sixteenth

16. What is the fuel for nuclear reactors that currently generate electricity?
(A) uranium
(B) hydrogen
(C) petroleum
(D) steam
(E) gasohol

17. Which radioisotope is often used in medical treatment to destroy diseased tissue?
(A) uranium-235
(B) uranium-238
(C) iodine-131
(D) technetium-99m

18. Which of the following is the primary source of energy that powers the sun?
(A) fission of uranium nuclei
(B) solar wind power
(C) reflected light from the moon
(D) steam turbines
(E) fusion of small nuclei to larger ones

19. In the year 2000, a large city hospital purchased 100 mg of Co-60 radioisotope. Given that the half life of Co-60 is close to five years, how much pure Co-60 would be expected to remain by the year 2010?
(A) 250 mg
(B) 100 mg
(C) 50 mg
(D) 25 mg

20. The half-life of a radioactive strontium - 90 is 28 years. Which of the following statements is true of a sample of 1.0 mg of it?
(A) After 28 years, there will be 0.5 mg left.
(B) After 28 years, there will be 0.30 mg left.
(C) After 28 years, there will be 30 mg left.
(D) After 28 years, there will be 0 mg left.
(E) After 28 years, there will be 2 mg left.

21. Which type of radiation contains the least amount of energy in each photon?
(A) ultraviolet
(B) visible
(C) infrared
(D) X-ray
(E) gamma ray

22. Why are control rods used in nuclear reactors along with fuel rods?
(A) The control rods absorb some neutrons to keep the reaction from going too fast
(B) The control rods help to convert ²³⁵U to ²³⁸U.
(C) The control rods absorb the heat to keep the reactor cool.
(D) The control rods keep the water from becoming radioactive.
(E) Without control rods, the uranium would convert to plutonium and blow up.

23. How does a nuclear reactor produce electricity?
(A) Nuclear explosions inside the reactor exert mechanical force against the pistons
(B) Energy is produced by the fission of nuclei, and this heat energy vaporizes water to drive a turbine
(C) The neutrons are absorbed by the control rods which propel them out of the reactor
(D) The nuclear reactions ignite chemical fires, and these flames power electric generators
(E) Beta particles are very fast electrons which race through electrical wires

24. What is meant by the term ENRICHED URANIUM?
(A) pure uranium with no other elements present
(B) all nuclei present are the isotope U-238
(C) uranium that has been rinsed in heavy water to remove impurities
(D) uranium that has a higher fraction of U-235 than occurs naturally
(E) uranium that has had gold added to stabilize it

25. What is the source of the energy evolved in nuclear fission ?
(A) the uranium burns in the presence of oxygen
(B) when a large nucleus splits apart, some mass is converted into energy
(C) neutrons are hurled out of the rapidly spinning nucleus by tremendous centrifugal force
(D) neutrons collide with electrons to form gamma radiation
(E) the U-235 nuclei fuse together with U-238

26. Which statement below is correct?
(A) neutrons can cause biological damage if they are moving very fast
(B) all radioactive nuclei have the same half-life
(C) all radioactivity on this planet is caused by human activities
(D) a helium nucleus can cause biological damage, even if at rest
(E) all products from a nuclear reactor are harmless to life

27. In one type of radioactive decay, a(n) _______ breaks down, releasing an electron.
(A) alpha particle
(B) beta particle
(C) neutron
(D) proton

28. The half-life of a radioactive iodine is 8 days. Which of the following statements is true of a sample of 1.0 mg of it?
(A) After 16 days, there will be 0.5 mg left.
(B) After 16 days, there will be 0.25 mg left.
(C) After 16 days, there will be 8 mg left.
(D) After 16 days, there will be none left.
(E) After 8 years, there will be 0.25 mg left.

29. What happened at Three Mile Island?
(A) An accident involving a nuclear power plant.
(B) The first perfect game in Major League Baseball was pitched.
(C) Site of the first above-ground test of a fusion bomb in 1958.
(D) Where Darwin visted aboard the H.M.S. Beagle to develop his theory of evolution.
(E) Future site of former President Bill Clinton’s Presidential Library.

30. Pick the one term or name that is not related to the other four.
(A) Yucca Mountain
(B) Chernobyl
(C) radon
(D) Bay of Pigs
(E) Glenn Seaborg



ANSWERS

1-B 2-A 3-B 4-E 5-D 6-B 7-A 8-D 9-D 10-C 11-C 12-E 13-A 14-B 15-C 16-A 17-C 18-E 19-D 20-A 21-C 22-A 23-B 24-D 25-B 26-A 27-C 28-B 29-A 30-D