Chapter 9:
Radioactivity and Nuclear Reactions
Practice Test
1.
How many beta particles are emitted when the nucleus 40/19 K decays to the nucleus 40/20 Ca?
a.
2
b.
1
c.
0
d.
20
Hint
2.
What is the ratio of neutrons to protons in the nucleus 241/95 Am ?
a.
0.39
b.
0.65
c.
2.54
d.
1.54
Hint
3.
A sample of radioactive carbon-14 sample has decayed to 12.5% of its original amount. If the half-life of carbon-14 is 5730 years, how old is this sample?
a.
5730 years
b.
17,190 years
c.
11,460 years
d.
22,920 years
Hint
4.
How long will it take a sample of 194/84 Po to decay to 1/8 of its original amount if the half life of 194/84 Po is 0.7 s?
a.
5.6 s
b.
1.4 s
c.
2.1 s
d.
0.7 s
Hint
5.
The half life of 131/53 I is 8.04 days. How much time would be needed to reduce 1 g of 131/53 I to 0.25 g?
a.
16.08 days
b.
24.12 days
c.
8.04 days
d.
32.16 days
Hint
6.
A sample of 38/17Cl is observed to decay to 25% of the original amount in 74.4 minutes. What is the half-life of 38/17 Cl?
a.
148.8 minutes
b.
74.4 minutes
c.
37.2 minutes
d.
24.8 minutes
Hint
7.
An alpha particle is the same as the helium nucleus 4/2 He. What nucleus is produced when the nucleus 226/88 Ra decays by emitting an alpha particle?
a.
222/88 Ra
b.
222/84 Po
c.
228/90 Th
d.
222/86 Rn
Hint
8.
How many neutrons are in the nucleus 56/26 Fe?
a.
30
b.
56
c.
82
d.
26
Hint
9.
How many alpha particles are emitted when the nucleus 222/86 Rn decays to 218/84 Po?
a.
2
b.
0
c.
1
d.
4
Hint
10.
How many protons are in the nucleus
81
36
Kr?
a.
117
b.
45
c.
36
d.
81
Hint
