Radioactivity Test Review
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
1. Radioactive materials have unstable a. electrons. b. nuclei. c. protons. d. neutrons.
2. Alpha radiation can be stopped by a. clothing. b. a sheet of paper. c. a wall. d. All of the above
3. The type of nuclear radiation that is the most dangerous is a. radons. b. gamma c. alpha d. beta
4. The process of nuclear change in an atom of radioactive material is called a. nuclear decay. b. isotopes. c. nuclear mass. d. radon.
5. Nuclear radiation refers to charged particles or energy emitted by an unstable a. proton. b. atom. c. nucleus. d. isotope.
6. In alpha decay, the mass number of the atom a. equals the sum of the mass numbers of the products. b. does not change after the decay. c. is the same as the atomic number. d. decreases by 4 amu.
7. What is a common source of radiation in our area? a. ice b. animals c. plutonium d. radon
8. During beta decay, a nucleus a. gives up two protons and two neutrons. b. maintains the same number of protons and neutrons. c. loses a proton and gains a neutron. d. gains a proton and loses a neutron.

9. When an atom undergoes gamma decay, the atomic number of the element a. remains the same. c. decreases by one. b. increases by one. d. increases by two.
10. In radioactive decay, with each successive half-life, half the remaining sample decays to form another a. animal. b. element. c. life-form. d. proton.
11. Nuclear fission is the: a.
Production of uranium. b.
Splitting of protons by bombarding them with neutrons. c.
Splitting of atoms by bombarding them with neutrons.
d. Result of neutrons smashing into each other.
12. During fission: a.
Electrons are released and cause more fission. b.
Protons are released and cause more fission. c.
Uranium is produced. d.
Neutrons are released and cause more fission.
13. The weapons grade fuel needed for the first atomic bomb was: a. Hydrogen b. Uranium-235 c. Uranium-238 d. Uranium-571
14. Separating U-235 from U-238 was a problem because: a.
There was so much more U-235 than U-238 b.
There was so much more U-238 than U-235. c.
A chain reaction would result. d.
They are chemically identical.
Questions 15- 22 (*= More than one answer MAY be needed.) a) alpha b) beta c) gamma d) omega
15. Reduces atomic number by 2 Alpha
16. Increases atomic number by 1 Beta
17. Made up of two protons and two neutrons Alpha
*18. Does not change mass number Beta & Gamma
19. Reduces mass number by 4 Alpha
*20. Does not change atomic number Gamma

22. Which of the following is the correct isotope formula? a)
150
61
Sm b)
61
150
Sm c)
153
62
Sm d)
62
153
Sm e)
153
63
Sm ab)
63
153
Sm
_______________________________________________________________
23. What is the atomic number of the element shown above? a) 2.456 b) 57 c) 83 d) 140 e ) 197 ab) 7980
24. What is the mass number of the element shown above? a) 2.456 b) 57 c) 83 d) 140 e ) 197 ab) 7980
25. How many protons does the element have in its nucleus? a) 2.456 b) 57 c) 83 d) 140 e ) 197 ab) 7980
26. How many neutrons does the element have in its nucleus? a) 2.456 b) 57 c) 83 d) 140 e ) 197 ab) 7980
The above is a model for radioactive decay. The entire rectangle represents 100% of the radioactive material with each individual block representing one atom. The portion that is NOT shaded represents atoms that have not yet decayed into something else.
27. How many half-lives have passed? a) 1 b) 2 c) 3 d) 4 e) 5
28. If the half-life of the element is 26 seconds how much time has passed according to the diagram? a) 13 seconds b) 26 seconds c) 52 seconds d) 78 seconds e) 104 seconds ab) 130 seconds
29. How many grams will decay in the next half-life? a) 2 b) 5 c) 10 d) 20 e) 40

Name _____________________________________ Period _______
Radioactivity Test Review Problems
1. Bismuth-207 has a half-life of 35 years. a) How much of 48 grams of Bismuth-207 is unchanged after five half-lives? b) How much of 48 grams of Bismuth-207 has decayed after five half-lives? c) How much time has passed in five half-lives of Bismuth-207?
1. Total time Number of half-lives
0
Unchanged material
48g
Decayed material
0g
35 years
70 years
105 years
140 years
175 years
1
2
3
4
5
24g
12g
6g
3g
1.5g
24g
36g
42g
45g
46.5g
2. Cerium-137 has a half-life of 9 hours. a) How much of 14.8 grams of Cerium-137 is unchanged after four half-
lives? b) How much of 14.8 grams of Cerium-137 has decayed after four half-lives? c) How much time has passed in three half-lives of Cerium-137?
1. Total time Number of half-lives
Unchanged material
Decayed material
0 14.8 g 0g
9 hours
18 hours
27 hours
36 hours
1
2
3
4
7.4g
3.7g
1.85g
0.925g
7.4g
11.1g
12.95g
13.875g

3. What is the mass number of Berkelium-247? 247
4. What is the atomic number of Berkelium-247?
5. What is the correct symbol for Berkelium-247?
247
97
Bk
Berkelium-247 undergoes alpha decay.
6. What is the mass number of the new element?
97
243
7. What is the atomic number of the new element? 95
8. What is the symbol for the new element?
243
95
Am
9. What is the mass number of Antimony-125? 125
10. What is the atomic number of Antimony-125?
11. What is the correct symbol for Antimony-125?
51
125
51
Sb
Antimony-125 undergoes beta decay.
12. What is the mass number of the new element? 125
13. What is the atomic number of the new element? 52
14. What is the symbol for the new element?
125
52
Te