Chapter
21
Multiple
Choice
Identify
the letter of the choice that best completes the statement or answers the
question.
____ 1. Materials that continue to glow in the dark
after they have been exposed to light are said to be _____.
|
a. |
radioactive |
c. |
phosphorescent |
|
b. |
unstable |
d. |
incandescent |
____ 2. The most difficult radiation to block out is
_____.
|
a. |
alpha particles |
c. |
gamma rays |
|
b. |
beta particles |
d. |
visible light rays |
____ 3. When 
becomes 
,
what type of decay has taken place?
|
a. |
alpha |
c. |
gamma |
|
b. |
beta |
d. |
positron |
____ 4. Which type of radiation is most penetrating?
|
a. |
alpha |
c. |
gamma |
|
b. |
beta |
d. |
They are equal. |
____ 5. What is the source of the electrons produced
in beta decay?
|
a. |
an outer energy level |
c. |
a neutron |
|
b. |
a valence electron |
d. |
a proton |
____ 6. The radiation detector that uses detection of
flashes of light is a _____.
|
a. |
bubble chamber |
c. |
Geiger counter |
|
b. |
film badge |
d. |
scintillation counter |
____ 7. Which of the following could be dated using
carbon-14?
|
a. |
ashes from a fire |
c. |
glacial deposits |
|
b. |
a rock |
d. |
lava fields |
____ 8. Two or more nuclei combine to form one larger
nucleus in the process of nuclear _____.
|
a. |
decay |
c. |
fusion |
|
b. |
fission |
d. |
tracing |
____ 9. The greatest source of radiation most humans
are exposed to is _____.
|
a. |
cosmic rays |
c. |
radon |
|
b. |
medical X rays |
d. |
rocks and soil |
____ 10. The radioisotope iodine-131 is used to
determine the health of the thyroid gland. Iodine-131 is an example of _____.
|
a. |
an allotrope |
c. |
radiation |
|
b. |
a tracer |
d. |
a structure |
Matching
Match each item with the correct statement
below.
|
a. |
alpha particle |
g. |
nuclear fission |
|
b. |
beta particle |
h. |
nuclear fusion |
|
c. |
deuterium |
i. |
nuclear reactor |
|
d. |
gamma ray |
j. |
radioactivity |
|
e. |
gray |
k. |
sievert |
|
f. |
half-life |
l. |
tritium |
____ 11. The unit of radiation used to measure the
amount of radiation received by an organism is called the _____.
____ 12. _____ is the reaction that occurs when two
small nuclei join together to form a larger nucleus.
____ 13. The spontaneous emission of radiation by a
nucleus is known as _____.
____ 14. The _____ is a unit of radiation that measures
the amount of radiation absorbed by a tissue.
____ 15. The isotope of hydrogen with a mass number of
3 is _____.
Short
Answer
16. What does the subscript on the nuclear symbol
for a beta particle, 
,
mean?
17. Name three different products formed in any
nuclear fission reaction.
18. The reactions that typically occur when a
neutron strikes a uranium-238 nucleus and a uranium-235 nucleus are different.
Explain how.
19. How does radiation affect the structure of a
stable molecule, such as a molecule of water?
20. Write the nuclear symbol for an alpha
particle.
21. Write the nuclear symbol for an atom of
deuterium.
22. Write the nuclear symbol for an atom of
silicon-28.
23. Complete the following nuclear equation: 
24. Complete the following nuclear equation: 
gamma
ray +
25. Complete the following nuclear equation: 
Problem
Technetium-99m is widely used in
diagnosing medical problems. The graph in Figure 21-1 shows the rate at which a
200-gram sample of technetium-99m decays. Answer the following questions using
the graph.
26. What is the half-life of technetium-99m?
27. Estimate the amount of the original sample of
technetium-99m that would remain after 1 h; after 10 h.
28. Suppose that a doctor needs 25 g of
technetium-99m in a medical procedure, and a sample of 100 g is made at 8:00
a.m. What is the latest time at which the procedure can be carried out? Why?
29. The technetium-99m is considered to be no
longer useable when less than 6 g remains. At what time would the sample
described in the preceding question become unusable?
30. Radioactive isotopes used for medical purposes
are usually produced in a nuclear laboratory and shipped to hospitals. What
problem can you see in producing and using technetium-99m by this system?