e.
binding energy
41. Magnetic confinement is used in controlled fusion experiments to
a.
provide neutrons
b.
accelerate nuclei
c.
control a plasma
d.
excite nuclei into higher energy levels
e.
inject energy into nuclei
42. Radioactive decay is involved in
a.
irradiating food to destroy harmful bacteria
b.
keeping the interior of the Earth hot
c.
making smoke detectors work
d.
finding flaws in jet engine parts
e.
all of the above
43. If one half life for an isotope is 25,000 years, then 10 half-lives would be _______ years.
a.
2,500
c.
125,000
b.
25,000
d.
250,000
44. The type of nuclear reaction taking place in stars is:
a.
cold fusion
c.
fission
b.
fusion
d.
beta decay
45. The nucleus of an atom is composed of protons and neutron held together by the
a.
binding energy
c.
fusion
b.
strong nuclear force
d.
fission
46. Hydrogen bombs get most of their energy from
a.
the fission of hydrogen
c.
strong nuclear energy
b.
the fusion of hydrogen
d.
nuclear binding energy
MULTIPLE RESPONSE
1. How do isotopes of a given element differ?
a.
They have different mass numbers.
b.
They have different neutron numbers.
c.
They have different atomic numbers.
d.
They have different quantum numbers.
e.
none of the above
2. The expression(s) indicating the mass number of a nucleus is
a.
A
b.
N
c.
Z
d.
Z + N
e.
A – Z
3. The expression(s) indicating the number of nucleons in a nucleus is
a.
A
b.
N
c.
Z
d.
Z + N
e.
A – Z
4. The expression(s) indicating the number of neutrons in a nucleus is
a.
A
b.
N
c.
Z
d.
Z + N
e.
A – Z
5. A magnetic field will deflect a(n)
a.
alpha particle
b.
beta particle
c.
gamma ray
d.
x ray
e.
all of the above
6. What sorts of materials serve as moderators in nuclear reactors?
a.
water
c.
graphite
b.
boron
d.
concrete
7. What isotopes are used as nuclear reactor fuel?
a.
uranium-235
c.
plutonium-239
b.
uranium-238
d.
deuterium
8. Why use nuclear power on a satellite?
a.
It can supply energy for many years on long space missions.
b.
Solar cells don’t work well in the outer solar system far from the sun.
c.
Sending radioactive materials into space is a good way to get rid of them so they
don’t create a hazard on earth.
d.
all of the above
9. Which of these is/are not true of nuclear fission reactors?
a.
Their intended output is heat.
b.
They produce the majority of the electric energy used in the world.
c.
There is a small chance one could explode like an atom bomb.
d.
Some can produce or “breed” more nuclear fuel than they consume.
10. Fission is used in
a.
atomic bombs
b.
power plants
c.
energy for stars
d.
hydrogen bombs
e.
a tokamak reactor
11. Fusion is used in
a.
atomic bombs
b.
power plants
c.
energy for stars
d.
hydrogen bombs
e.
a tokamak reactor
12. Cold fusion has
a.
solved the world’s energy crisis
b.
been used to create superheavy elements
c.
been achieved using muons
d.
rendered nuclear reactors obsolete
13. Of the thousands of different isotopes known to exist,
a.
most of them are radioactive
b.
only a couple can be used to build an atom bomb
c.
some are used in medical diagnosis and treatment
d.
most occur naturally
e.
all of the above
14. Fuel rods in a nuclear reactor contain only about 3% uranium-235 and the remainder is
mostly uranium-238. As the uranium-238 absorbs a neutron during reactions, it becomes
uranium-239, which undergoes two beta decays to become plutonium-239.
a.
uranium-239
c.
plutonium-239
b.
uranium-237
d.
plutonium-238
COMPLETION
1. The number of protons in a nucleus is the __________ number.
2. Two isotopes have the same __________ number.
3. The symbol indicating the atomic number of a nucleus is __________.
4. The symbol indicating the number of protons in a nucleus is __________.
5. The symbol indicating the mass number of a nucleus is __________.
6. The symbol indicating the number of nucleons in a nucleus is __________.
7. The symbol indicating the number of neutrons in a nucleus is __________.
8. An alpha particle is another name for a(n) __________.
9. A beta particle is another name for a(n) __________.
10. A gamma ray is another name for a(n) __________.
11. Nuclear radiation can be detected by using a __________.
12. Of the three types of nuclear decay, only __________ does not affect the atomic number of
the nucleus.
13. Two particles that will be deflected by a magnetic field are __________ and __________.
14. When radium-223 (Z = 88) decays to radon-119 (Z = 86), the other particle emitted is a(n)
__________.
15. When sulfur-35 (Z = 16) decays to chlorine-35 (Z = 17), a(n) __________ is emitted.
16. When a neutron decays to a proton, a(n) __________ particle is emitted.
17. When a nucleus in an excited state decays to the ground state, a(n) __________ particle is
emitted.
18. The time interval during which a nucleus has a 50% probability of decaying is its
_________.
19. The half life of uranium-232 is 70 years. The time for 3/4 of a sample of uranium-232 to
decay is __________.
20. A Geiger counter registers a count rate of 8,000 counts per minute from a sample of a
radioisotope. The count rate 24 minutes later is 1,000 counts per minute. The half life of the
radioisotope is __________.
21. The Voyager space probes used electricity provided by __________.
22. Stars are powered by ________.
23. If a piece of wood is suspected to be several thousand years old, its true age can likely be
determined through use of the isotope _________.
24. How tightly the nucleons in a nucleus are bound together is indicated by the nucleus’s
__________.
25. The splitting of a large nucleus into two smaller nuclei upon absorbing a neutron is
__________.
26. The combining of two nuclei to form a larger nucleus with the release of energy is
__________.
27. Two things that exploit fission are __________ and __________.
28. In a nuclear reactor, _________________ are used to limit the number of neutrons passing
from one fuel rod to another.
29. The determination of the composition of a material by bombarding it with neutrons and
monitoring the emitted radiation is __________.
30. When uranium-238 (Z = 92) is bombarded with a neutron, it can change into __________.
31. The mass of an atom of carbon-12 (Z = 6) is less than the mass of 6 protons and 6 neutrons
because of __________.
32. Isotopes of a given element have the same number of _____________ in the nucleus.
33. In a smoke detector, current flows between the plates because the radiation ___________
the air.
34. An important factor in producing and controlling a fission chain reaction is the fact that
_________ neutrons are much better a causing fission in uranium-235.
MATCHING
Match each item with the correct statement below.
a.
alpha particle
h.
hydrogen bomb
b.
atomic bomb
i.
neutron activation analysis
c.
atomic mass number
j.
neutron number
d.
atomic number
k.
nuclear fission
e.
beta particle
l.
nuclear fusion
f.
binding energy
m.
tokamak
g.
half-life
1. exploits nuclear fusion
2. the number of protons in a nucleus
3. time interval during which a nucleus has a 50% probability of decaying
4. the total number of nucleons in a nucleus
5. the splitting of a large nucleus into two smaller nuclei
6. the same as a helium-4 nucleus
7. indicates how tightly bound together a nucleus is
8. involves inducing radioactivity artificially
9. one design for a controlled fusion reactor
10. this particle is simply an electron ejected from a nucleus
SHORT ANSWER
1. Two areas in which fusion is the source of energy are __________ and __________.
PROBLEM
1. A nucleus of radium-223 undergoes alpha decay. (a) Write the reaction equation and (b)
determine the identity of the daughter nucleus.
2. A nucleus of sulfur-35 undergoes beta decay. Write the reaction equation and determine the
identity of the daughter nucleus.
3. A Geiger counter registers a count rate of 8,000 counts per minute from a sample of a
radioisotope. The count rate 24 minutes later is 1,000 counts per minute. What is the half-
life of the radioisotope?
4. Lithium, Li-7, contains three protons and four neutrons and has a mass of 7.01600 u. What
is the mass defect for this nucleus in atomic mass units?