Nuclear Fission

• What is nuclear fission?

  The splitting of a large and unstable nucleus
• What happens when the unstable nuclei absorbs a neutron?

  it splits into two smaller nuclei, roughly equal in size and then it emits two or three neutrons and gamma rays
• What's released by the fission reaction?

  Energy
• What could happen to the neutrons that have been emitted?

  • May collide with another radioactive nucleus
  • this nucleus then absorbs the neutron and becomes unstable
  • this nucleus splits, releasing another neutron and produces more energy
• What happens after the nucleus splits?

  it leaves two smaller nuclei roughly equal in size

  And they both have kinetic energy
• What happens if the chain reaction isn't controlled?

  It will increase at an exponential rate - which is what happens in a nuclear weapon
• Describe the process of nuclear fission inside a nuclear reactor?

  neutron absorbed by a uranium nucleus

  nucleus splits into two parts

  and (2/3) neutrons (are released)

  and gamma rays (are emitted)
• Explain how the process of nuclear fusion leads to the release of energy?

  lighter nuclei join to form heavier nuclei

  some of the mass (of the nuclei) is converted to energy (of radiation)
• Describe the process of Nuclear Fission (4 marks)

  -a neutron is absorbed by a (large) nucleus

  -the nucleus splits into two (smaller) nuclei

  -releasing energy (and gamma rays)

  -and (two / three) neutrons
• Why do we use control rods in nuclear reactors?

  they absorb neutrons and slow down the chain reaction.
• What are the pros of nuclear energy?

  • Nuclear fuel such as uranium or plutonium is relatively cheap
  • Nuclear power plants can produce large and steady electric power
  • Nuclear power does not produce any greenhouse gas