Nuclear Reactions

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Nuclear Reactions

• PS 2.6 2.7

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Fission vs. Fusion

• Nuclear Reactions occur within a heavy atom (not
  between 2 or more atoms) ex. uranium
• 1. Fission when a nucleus splits into 2 or more
  parts releasing lots of energy!
• How does it work?
• A. A neutron penetrates the nucleus of an atom
• B. As nucleus splits, it becomes a smaller nuclei
  (which also releases more neutrons)

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1. Chain reaction occurs if one or more ejected
neutrons strikes another nucleus more split

• 2. Chain reactions occur in power plants bombs
• 3. The mass of the products is less than what you
  start with (reactants).
• Why?
• Emc2 Where did the mass go?

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2. Fusion occurs when light nuclei (hydrogen)
combine to make larger nuclei (helium)

• A. Naturally occurs on the sun (in stars)
• B. Energy is released as nuclei combine.
• C. Requires huge amounts of energy, but it
  releases more energy than is needed to start it.
• D. Fusion for human use is still in development!

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3. Nuclear Technology in Use

• Medicine
• 1. radiation to destroy cancer (fast-growing
  cells)
• 2. radiation can allow us to view organ systems
  by tracking where it goes.
• 3. difficult to not damage healthy cells
• 4. waste products are dangerous

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B. Weapons

1. Deterrent to war (enough to destroy all life)
2. Easily smuggled
3. Huge destruction

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• 4. Contaminate environment
• 5. Waste is dangerous for thousands of years

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C. Power used to produce electricity (Catawba on
Lake Wylie)

1. A controlled fission reaction is used to heat
   water into steam (spins magnet) that creates
   electron flow (electricity)

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2. Benefits a. high energy from little fuel

• b. no CO2 pollution
• c. abundant fuel
• 3. Drawbacks
• a. thermal pollution to water systems
• b. waste is extremely dangerous
• c. leaks or explosions are devastating

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Chernobyl