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NUCLEAR PACKET
Subatomic Particles (Review)
1.
Element carbon is atomic number 6. How many protons and electrons are in a carbon atom?
2.
The atomic number of an element is 11. What is the element?
3.
What is the number of protons, electrons and neutrons in the nucleus of sodium-23 atom?
4.
How many protons, electrons, and neutrons are in the following atoms?
Atomic Number Mass Number
5.
# Protons
# Neutrons
# Electrons
a. Beryllium (Be)
4
9
_______
_______
_______
b. Neon
10
20
_______
_______
_______
c. Sodium
11
23
_______
_______
_______
Complete this table.
Name of
Element
Symbol
Atomic
Number
7
Mass Number
Number of
Protons
9
39
59
27
Al
Number of
neutrons
7
10
Number of
electrons
19
27
6.
Two of the isotopes of carbon are carbon-12 and carbon-14. Give the nuclear symbol for each.
7.
Determine the number neutrons in the following atoms?
a.
8.
16
8 O_______
32
16
b.
S
_______ c.
61
47 Ag
_______ d.
45
35 Br
_______ e.
125
82 Pb_______
Using the Periodic Table, determine the number of neutrons in these atoms.
a. 12C _______ b.
15
N
c.
226
Ra _______
9.
What are the charges and relative masses of the three subatomic particles that are found in the atom?
10.
Describe the composition of the nucleus of the atom.
11.
What does the atomic number of each atom represent?
12.
Name three ways that isotopes of an element differ.
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Half Life
Solve the following problems. Show all work.
1.
2.
Phosphorus-32, 15P, a radioactive isotope of phosphorus, has a half-life of 14.3 years.
How many grams of phosphorus will remain after 57.2 years if you have 4.0 g of the
isotope at the beginning?
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How many years will be needed for the decay of
of a given amount of Ra-226 with a
16
half-life of 1620 years.
3.
The half-life of polonium-210 is 138.4 days. What fraction will remain after 415.2
days?
4.
The half-life of thorium-227 is 18.72 days. How many days are required for threefourths of a given amount to decay?
5.
The half-life of protactinium-234 is 6.75 hours. How much of a given amount remains
after 27.0 hours?
6.
The half-life of radon-222 is 3.823 days. What was the original mass of radon-222 if
0.500 g remains after 7.646 days?
7.
Determine the age of each of the following specimens:
a. Scientists have discovered that only 2.5 grams of carbon-14 remain in a sample that
originally contained 10 grams. Half-life of C-14 is 5700 years.
b. From 10.0 grams of radium-226, 5.0 grams remain. The rest of the radium has
changed to lead. Half-life of radium is 1620 years.
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Nuclear Equations:
U  24 He  ______
1.
238
92
2.
234
90
3.
234
91
4.
234
92
5.
230
90
6.
226
88
Th 10 e  ______
Pa 10 e  ______
U  24 He  ______
Th    ______
Ra  _____  222
86 Rn
7. _____  24 He  218
84 Po
Po    ______
8.
218
84
9.
214
82
Pb    _____
10. _____    214
84 Po
Po  _____  210
82 Pb
11.
214
84
12.
210
82
Pb 
0
1
13. _____ 
14.
e  _____
0
1
e 210
84 Po
Po  _____  24He
210
84
15.
14
7N
16.
235
92 U
+
+
4
2
He →
1
0n
→
17
8O
138
56
+ ?
Ba + 3 01 n + ?
4 11 H → (fusion reaction) ???
3
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MULTIPLE CHOICE
1. Invisible rays, emitted from uranium crystals, that affect a photographic plate were discovered by
a. Curie
b. Becquerel
c. Lawrence
d. Einstein
2. Elements that have the same atomic numbers but different atomic masses are called
a. ions
b. nonmetals
c. metalloids
d. isotopes
3. A radioactive isotope of carbon is
a. C-4
b. C-12
c. C-14
d. C-6
4. When a radioactive element emits radiation and changes to a different element, it is said to undergo
a. a physical change
b. a chemical change
c. a radioactive decay
d. atomic fusion
5. An alpha particle is a
a. a helium nucleus
c. helium atom
b. a hydrogen nucleus
d. a hydrogen atom
6. High speed electrons emitted from the nuclei of atoms are called
a. beta particles
b. gamma rays
c. alpha particles
7. A sheet of aluminum can stop
a. gamma rays
b. gamma rays and alpha particles
d. ions
b. alpha particles and beta particles
d. beta particles and gamma rays
8. Gamma rays are most similar to
a. Radio waves
b. visible light waves
c. sound waves
d. X rays
9. When an uranium atom is subjected to neutron bombardment, the atom is
a. destroyed
b. disintegrated
c. ionized
d. split
10. When a uranium-238 atom decays, it emits an alpha particle. The atomic mass of the new atom
formed is
a. decreased by 2
b. decreased by 4
c. increased by 4
d. increased by 2
11. The final stable element formed from the radioactive decay of uranium is
a. thorium
b. lead
c. plutonium
d. silver
12. When an atom of nitrogen emits an alpha particle
a. the atom disintegrates
b. atomic fission takes place
c. carbon is formed
d. oxygen is formed
13. If an original sample of carbon-14 weighs 10.0 grams and the half-life of carbon-14 is 5700 years,
then at the end of 5700 years the amount of carbon-14 remaining will be
a. 2.5 g
b. 5.0 g
c. 10.0 g
d. 8.0 g
14. When an atom of uranium undergoes fission, the noble gas produced is
a. argon
b. neon
c. krypton
d. xenon
15. In a nuclear reactor, neutrons are slowed down by the
a. moderator
b. control rods
c. fuel element
d. shielding
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16. In nuclear fusion, when 4 atoms of hydrogen fuse
a. one atom of nitrogen is formed
b. a chemical change takes place
c. one atom of helium is formed
d. a physical change takes place
17. Radioisotopes that are used to track chemical pathway are called
a. ions
b. tracers
c. atomic cocktails
d. radiators
18. Changes in heredity that may be produced by radiation are called
a. transformations
b. mutations
c. chemical changes
d. physical changes
TRUE/FALSE
19. An element that emits rays is said to be contaminated.
20. Unstable isotopes of elements are called radioisotopes.
21. The symbol represents tritium.
22. Gamma rays can be stopped by an aluminum sheet.
23. The change of an atom into a new element is called a chemical change.
24. The first artificial transmutation was performed by Albert Einstein.
25. The rate at which a radioactive element decays is known as the half-life.
26. Devices used in smashing atoms are called atom smashers.
27. The splitting of an atom into two fragments of approximately the same size is called nuclear fusion.
28. The self continuation of nuclear fission is called a chain reaction.
29. A device used to control a nuclear chain reaction is a bubble chamber.
30. The sun produces its energy by thermonuclear reactions.
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