ANSWERS
Nuclear Chemistry Review Questions
1. Compare the mass, charge, and penetration power of alpha, beta and gamma radiation.
Alpha
Beta
Gamma
Mass
4
0
0
Charge
+
0
Penetration
Lowest
Middle
Highest
2. In 5.49 seconds, 1.20g of argon-35 decays to leave only 0.15g. What is the half-life?
1.20g  0.60g  0.30g  0.15g , therefore it took 3 half-life periods.
5.493 = 1.83 sec
3. How many days does it take 16.0g of gold-198 to decay to 1.0g?
16.0g  8. 0g  4.0g  2.0g  1.0g , therefore 4 half-life periods
From Ref Table N, 1 half-life = 2.69d
2.69d * 4 = 10.76 days
4. Why does an atom undergo radioactive decay?
Because it has an unstable nucleus
5. Compare and contrast fission and fusion. Why is fission used for electrical and fusion is
not?
Fission=Division, the splitting of large unstable atoms(nucleus)
Fusion=joining together, small isotopes of H, creates way more energy
6. How is nuclear chemistry applied to medicine? What type of radioisotope must be used
when it is injected into a person?
Radioisotopes are used to treat and diagnose illnesses
If injected they must have short half-lives and quickly removed from the body
7. Write out the nuclear decay of radium-226.
226
4
222
88 Ra  2 He  86 Rn
8. What is different about nuclear reactions when compared to a chemical reaction?
Nuclear reactions transform atoms into other atoms, chemical reactions involved
the rearrangement of electrons
9. At what point do all isotopes of an element become radioactive?
Up to and including atomic # 83
ANSWERS
10. Think about using nuclear power. What are three advantages and disadvantages of
using this as a power source?
Advantages
Disadvantages
-cheap power
-storage of wastes
-no greenhouse gases
-possible radiation leaks
-can supply electricity efficiently
-terrorist targets
11. What is the difference between artificial and natural transmutation? How can you identify
from an equation?
Artificial transmutation is induced by another particle colliding with the nucleus, it
can be identified by having two different reactant particles. (see b in #12)
Natural transmutation is the spontaneous decay of one atom into another atom
12. Complete the following:
He 11 H42 He  ____ 10 e
b.
3
2
1
0
c.
14
6
d.
226
88
a.
139
1
n 235
92 U 56 Ba 30 n  _____
C 01 e  _____
14
7
94
36
Kr
N
Ra  222
86 Rn  ______
4
2
He
13. List two benefits of radioactivity for humans. You cannot use any medicinal application.
Industrial measurement and food irradiation
Use the paragraph below to answer questions 14-17.
The first atom of element 112 was created and confirmed by a research team in 1996.
The element was created by bombarding lead foil with highly ionized zinc atoms. The single
atom of the new element decayed after 280 microseconds, losing an alpha particle to form
element 110.
14. What is the symbol for element 112? Uub
15. Write the chemical symbol and name of an element whose chemical properties are likely
to be similar to those of element 112? Explain your answer.
Any element in Group 12, so Zn, Cd, or Hg
16. Show how a combination of the atomic numbers of zinc and lead could account for the
formation of a nucleus of the new element described in the passage.
30Zn and 82Pb = 112Uub
17. Write the equation to show the radioactive decay of
223
227
4
112 Uub  2 He + 110 Kr
227
112
Uub as described in the passage.