Download Physical Science: Nuclear Chemistry Study Guide

Physical Science: Nuclear Chemistry Study Guide
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
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1. Radioactive materials have unstable
a. electrons.
c. protons.
b. nuclei.
d. neutrons.
2. After the nucleus of a radioactive element undergoes changes, the element can transform into
a. a different isotope of the same element.
b. an entirely different element.
c. Both (a) and (b)
d. Neither (a) nor (b)
3. Alpha particles
a. are positively charged.
b. consist of two protons and four neutrons.
c. can penetrate any thickness of matter.
d. All of the above
4. Which of the following is not a type of nuclear radiation?
a. alpha particles
c. neutron emission
b. beta particles
d. X rays
5. The process of nuclear change in an atom of radioactive material is called
a. nuclear decay.
c. nuclear mass.
b. isotopes.
d. radon.
6. Nuclear radiation refers to charged particles or energy emitted by an unstable
a. proton.
c. nucleus.
b. atom.
d. isotope.
7. Alpha particles are nuclei of
a. oxygen.
c. helium.
b. nitrogen.
d. radium.
8. As beta particles ionize they
a. lose energy.
c. neither lose nor gain energy.
b. gain energy.
d. None of the above
9. In this example, what are the chemical symbols of the products of the decay?
a. Ra and Rn
c. Rn and He
b. Ra and He
d. He is the only product.
10. During beta decay, a nucleus
a. gives up two protons and two neutrons.
b. maintains the same number of protons and neutrons.
c. loses a proton and gains a neutron.
d. gains a proton and loses a neutron.
11. Nuclei with too many or too few neutrons are
a. never found.
c. unnatural.
b. unstable.
d. stable.
12. The process of the production of lighter nuclei from heavier nuclei is called
a. mass energy.
c. magneticism.
b. fusion.
d. fission.
13. Fusion occurs when nuclei
____ 14.
____ 15.
____ 16.
____ 17.
____ 18.
____ 19.
____ 20.
a. split.
c. mutate.
b. combine.
d. gain energy.
The opposite reaction to fusion is called
a. beta decay.
c. fission.
b. alpha decay.
d. neutron transmission.
A fission chain reaction can be slowed by using materials that will
a. absorb some of the neutrons.
b. convert some of the neutrons to protons.
c. increase the rate of the neutron multiplication.
d. decrease the amount of available oxygen in the air.
You prepare a large screened-in box, inside which you place several dozen mouse traps. You set each trap and
on each mouse trap you place a ping pong ball. You then drop another ping pong ball into the box, which sets
off one of the mouse traps, which sets off other mouse traps, and so on. You have just demonstrated
a. a chain reaction.
c. the theory of relativity.
b. rat death.
d. alpha decay.
To treat certain brain tumors, doctors can use small beams of _____ that are focused to kill only the tumor
cells.
a. X rays
c. alpha rays
b. beta rays
d. gamma rays
What is the process in which an unstable atomic nucleus emits charged particles or energy or both?
a. radioactivity
c. decomposition
b. oxidation
d. none of the above
What type of nuclear decay produces energy instead of a particle?
a. alpha decay
c. gamma decay
b. beta decay
d. electron decay
The half-life of tritium, or hydrogen-3, is 12.32 years. After about 37 years, how much of a sample of tritium
will be left?
a.
c.
b.
d.
____ 21. The half-life of a radioisotope is the amount of time it takes for
a. half the sample to decay.
b. all the sample to decay.
c. the age of an artifact to be calculated.
d. detectable radiation to be absorbed by a sample.
____ 22. Carbon-14 has a half-life of 5730 years. If the age of an object older than 50,000 years cannot be determined
by radiocarbon dating, then
a. carbon-14 levels in a sample are undetectable after approximately ten half-lives.
b. carbon-14 levels in a sample are undetectable after approximately nine half-lives.
c. the half-life of carbon-14 is too long to accurately date the object.
d. a radioisotope with a shorter half-life should be used to date the object.
____ 23. Which of the following is NOT an advantage of using a fusion reaction instead of a fission reaction to
produce energy?
a. Workers are not in as much danger from radiation.
b. Hydrogen is used, and hydrogen is easily obtained from water.
c. No harmful waste products are produced.
d. Fusion reactors require less energy than fission reactors do.
Completion
Complete each sentence or statement.
24. An alpha particle is the same as a(an) ____________________ nucleus.
25. In the symbol He, the superscript 4 is the _________________________ for helium, and the subscript 2 is
the _________________________ for helium.
26. You want to be shielded from all three types of nuclear radiation. If you find shielding that blocks
____________________ radiation, then it will most likely also block the other two types.
Short Answer
27. What are massive, positively charged particles emitted by some radioactive elements?
28. What is the time required for half a sample of radioactive nuclei to decay called?
29. After three half-lives, what fraction of the original radioactive element remains?
30. To determine the age of fairly recent remains (in the tens of thousands of years as opposed to millions of
years), scientists compare the ratio of what two elements?
31. Potassium-40 decays into argon-40. Geologists use a technique to calculate the age of very old rocks by
comparing the ratio of the amount of potassium-40 to argon-40. What is the technique?
32. The equivalence of mass and energy means that matter can be converted into energy and energy into matter.
Write the equation that expresses this equivalence.
33. What is the process by which a nucleus splits into two or more smaller fragments, releasing neutrons and
energy, called?
34. What is the name for the process in which light nuclei combine at extremely high temperatures, forming
heavier nuclei and releasing energy?
35. What is one example of a place where naturally occurring extreme temperatures provide the energy needed to
bring hydrogen nuclei together in a fusion reaction?
36. Name one good use of the energy produced in a controlled chain reaction.
37. What is nuclear radiation that is emitted from natural sources all around us called?
38. Ionization occurs when atoms lose or gain what?
39. What type of nuclear radiation can travel farthest through matter?
40. All three types of nuclear radiation have just been released simultaneously and are headed your way. Which
will arrive first, which will have the greatest potential to cause damage to your tissues, and what can you do to
protect yourself against each?
41. Compare and contrast the processes of fission and fusion.
Problem
42. Astatine-218 has a half-life of 1.6 s. Suppose you have a 1.2-g sample of astatine-218. How much of the
sample remains unchanged after 6.4 seconds?
43. A sample of phosphorus-32 has a half-life of 14 days. If 25 g of this radioisotope remain unchanged after
approximately 56 days, what was the mass of the original sample?
44. After 15 minutes, 30 g of a sample of polonium-218 remain unchanged. If the original sample had a mass of
960 g, what is the half-life of polonium-218?
Other
Figure 10-3
45. Calculating Study Figure 10-3. How much nitrogen-14 will be produced from a 200-g sample of carbon-14
after 17,190 years?