Name: _____________ANSWER KEY_______________ Date: ____________________________________ Period: ________
Unit 5 – Nuclear Chemistry – Quiz Study Guide
1. Describe the mass, charge, actual identity, and relative penetration power of the following radioactive particles:
a) Alpha particles - Helium atom, mass of 4, charge (atomic number) of 2,
4
He, can be blocked by paper
2
0
e, can be blocked by wood
−1
0
c) Gamma particles – energy (electromagnetic radiation), mass of 0, no charge,
ɣ, can be blocked by
0
concrete
b) Beta particles - electron, no mass, -1 charge,
2. Compare and contrast fission and fusion.
Fission – nuclei split into two parts. A neutron hits it, splits it, sending more neutrons out, to hit more atoms 
tons of energy!
Fusion – nuclei of atoms fuse together (example: sun).  way more energy, but not way to harness it or create it
in a lab… yet
The atomic bomb is an example of _fission__. The Hydrogen bomb is an example of __fusion___.
3. Write nuclear reactions for the following:
14
a. Carbon-14 emits beta particles.
H
6
b.
c.
d.
e.
f.
g.
0
 −1
e +
14
N
7
232
4
228
Thorium-232 goes through alpha decay.
Th

He
+
Ra
90
2
88
226
Radium-226 emits gamma and alpha particles.
Ra  222
Rn + 42 He + 00 ɣ
88
86
0
36
Chlorine-36 undergoes positron emission.
Cl  36
S + +1
e
17
16
14
0
Nitrogen-14 goes through electron capture.
N + −1
e  14
C
7
6
37
0
Argon-37 is produced by beta decay.
Cl  37
Ar + −1
e
17
18
261
Fermium-257 is formed by alpha and gamma emission.
No  257 Fm + 42 He
102
100
+ 00 ɣ
4. Fill in the blanks and identify the type of decay:
210
83
Bi  0 e +
-1
210
84
Po
Beta
234
91
Pa 
0
e +
+1
234
90
Th +
0
ɣ
positron and gamma emission
0
5. Gold-191 has a half-life of 12.4 hours. What mass of this isotope would remain after 49.6 hours if you started
with a 7.50 mg?
49.6/12.4 = 4
7.5  3.75  1.875  0.9375  0.469 mg
6. The half-life of cesium-137 is 30.2 years. If the initial mass of a sample of cesium-137 is 1.00 kg, how much will
remain after 151 years?
151/30.2 = 5 half lives 1.00  0.5  0.25  0.125  0.0625  0.03125 kg
7. Given that the half-life of carbon-14 is 5730 years, consider a sample of fossilized wood that, when alive, would
have contained 24 g of carbon-14. It now contains 1.5 g of carbon-14. How old is the sample?
24  12  6  3  1.5
4 half lives x 5730 = 22920 years
8. What is the half-life of an isotope of plutonium, if the original sample was 10 g and after 420 days there were 1.3
grams left?
10  5  2.5  1.25 (1.3)
3 half lives
420/3 = 140 days