Section 30.2
Nuclear Decay and Reactions
Practice Test
1.
Fusion reactions are often called _________ reactions because of the large amounts of thermal energy required for fusion to occur.
a.
thermonuclear
b.
fission
c.
critical mass
d.
chain
Hint
2.
A radioactive lead isotope,
, undergoes beta decay and becomes bismuth. Write the nuclear equation.
a.
b.
c.
d.
Hint
3.
A large nucleus splits into two smaller ones. This is __________.
a.
annihilation
b.
production
c.
fission
d.
fusion
Hint
4.
According to Figure 30-4, what percentage of the original sample of a radioactive substance would be left after 10 half-lives?
a.
10%
b.
12.5%
c.
0.09%
d.
5%
Hint
5.
Why is the following reaction desirable as a power source?
a.
this cannot reach a chain reaction
b.
there's no radioactive waste
c.
there are no neutrons produced
d.
this isn't nuclear
Hint
6.
Carbon-14 decays to nitrogen-14 by emitting a beta particle. What happens to the total charge in the atom?
a.
decreases, but very slightly
b.
increases by two
c.
decreases by two
d.
remains the same
Hint
7.
Fusion occurs when __________.
a.
a large nucleus is split
b.
two smaller nuclei combine to form a larger one
c.
radioactive particles are emitted from the nucleus
d.
nuclei decay
Hint
8.
Write the nuclear equation for the transmutation of the radioactive thorium isotope
into the radium isotope
by the emission of an ? particle.
a.
b.
c.
d.
Hint
9.
Which decay does not result in transmutation?
a.
alpha
b.
beta
c.
gamma
d.
nuclear
Hint
10.
According to Figure 30-4, what percentage of the original sample of a radioactive substance would be left after 4 half-lives?
a.
6.25%
b.
25%
c.
50%
d.
12.50%
Hint
11.
What happens in a chain reaction?
a.
Neutrons released from nuclear fission strike other nuclei and cause them to undergo fission.
b.
Electrons released from nuclei strike other nuclei and cause them to break apart.
c.
Protons released from nuclei strike other nuclei and cause them to break apart.
d.
Neutrons stop reactions in the material.
Hint
12.
Write the nuclear equation for the transmutation of the radioactive actinium isotope
into the thorium isotope
by the emission of a
particle.
a.
b.
c.
d.
Hint
13.
Why are neutrons often used to bombard nuclei?
a.
They have no charge.
b.
They are very heavy.
c.
They are easily made.
d.
They move very fast.
Hint
14.
From where does the energy in a nuclear reaction come?
a.
The energy equivalence of the difference in mass of the reactants and the products
b.
The difference in mass between the protons and neutrons
c.
The mass of the neutrons in isotopes
d.
The entire mass of the atoms
Hint
15.
Which describes radiation in order of lowest to highest energy?
a.
beta, gamma, alpha
b.
gamma, beta, alpha
c.
alpha, gamma, beta
d.
alpha, beta, gamma
Hint
16.
How long does a sample of lead-236 with a half life of 2.85 years take to reduce to 1/8 its original amount?
a.
8.55 years
b.
22.8 years
c.
5.70 years
d.
2.85 years
Hint
17.
Write the nuclear equation for the transmutation of a polonium isotope,
, into a lead isotope,
, by the emission of an alpha particle.
a.
b.
c.
d.
Hint
18.
Based only on the information from Figure 30-5 and Table 30-2, which of the following would be the best choice to inject for a PET scan?
a.
uranium 235
b.
polonium 194
c.
lead 212
d.
polonium 210
Hint
19.
Which of the following medical examination tools does not use radiation?
a.
radioactive tracing
b.
ultrasound
c.
PET scans
d.
X rays
Hint
20.
When
is bombarded by
and results in
what else is emitted?
a.
a positron
b.
a neutron
c.
a proton
d.
an electron
Hint
21.
What does a moderator do in a nuclear reaction?
a.
increases the amount of fission
b.
slows fast neutrons
c.
speeds up slow neutrons
d.
absorbs neutrons
Hint
22.
What is the purpose of control rods in a nuclear reactor?
a.
to absorb protons
b.
to absorb isotopes
c.
to absorb neutrons
d.
to absorb electrons
Hint
23.
How is steam converted to electricity after a fission reaction?
a.
by turbines
b.
by moving water
c.
by moving through a paddle wheel
d.
by condensation
Hint
24.
Which of the isotopes described in Table 30-2 loses the greatest fraction of its mass when it decays?
a.
polonium 210
b.
polonium 194
c.
hydrogen 3
d.
cobalt 60
Hint
