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Basic Chemistry Copyright © 2011 Pearson Education, Inc.1
Chapter 16 Nuclear Radiation
16.6 Nuclear Fission and Fusion
Basic Chemistry Copyright © 2011 Pearson Education, Inc.2
In nuclear fission, • a large nucleus is bombarded with a small
particle• the nucleus splits into smaller nuclei and
several neutrons• large amounts of energy are released
Nuclear Fission
Basic Chemistry Copyright © 2011 Pearson Education, Inc.3
Nuclear FissionWhen a neutron bombards U-235,• an unstable nucleus of U-236 forms and
undergoes fission (splits)• smaller nuclei are produced such as Kr-91 and
Ba-142• neutrons are released to bombard more U-235
nuclei
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Nuclear Fission
1 235 236 91 142 10 92 92 36 56 0 + U U Kr + Ba + 3 + energyn n
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Chain Reaction
A chain reaction occurs • when a critical mass of uranium undergoes
fission• releasing a large amount of heat and
energy that produce an atomic explosion
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Chain Reaction
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Learning CheckSupply the missing atomic symbol to complete theequation for the following nuclear fission reaction.
1 235 137 10 92 52 0 + U Te + ? + 2 + energyn n
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Solution
1 235 137 10 92 52 0
97 40 + U Te + + 2 + e r yZr ne gn n
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Nuclear Power PlantsIn nuclear power plants, • fission is used to produce energy• control rods in the reactor absorb
neutrons to slow the fission process
Nuclear power plants supply about 10% of the electricity in the United States.
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Nuclear Power Plants
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Nuclear FusionNuclear fusion• occurs at extremely high temperatures
(100 000 000 °C)• combines small nuclei into larger nuclei• releases large amounts of energy• occurs continuously in the sun and stars
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Nuclear Fusion
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Indicate if each of the following is1) nuclear fission or 2) nuclear fusion___ A. a nucleus splits ___ B. large amounts of energy are released___ C. small nuclei form larger nuclei___ D. hydrogen nuclei react___ E. several neutrons are released
Learning Check
Basic Chemistry Copyright © 2011 Pearson Education, Inc.14
Indicate if each of the following is1) nuclear fission or 2) nuclear fusion 1 A. a nucleus splits 1, 2 B. large amounts of energy are released 2 C. small nuclei form larger nuclei 2 D. hydrogen nuclei react 1 E. several neutrons are released
Solution
Basic Chemistry Copyright © 2011 Pearson Education, Inc.
Concept Map
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