nuclear fission

• what is nuclear fission?

  the splitting of large & unstable nucleus e.g. uranium or plutonium
• what usually needs to happen for fission to occur?

  • unstable nucleus must absorb a neutron
  • spontaneous fission is rare (no neutron absorption)
• what is emitted in a fission reaction?

  • 2 or 3 neutrons
  • gamma rays
  • energy
• what does the nucleus undergoing nuclear fission split into?

  two smaller nuclei , roughly equal in size
• what form of energy do all products of nuclear fission have?

  kinetic energy
• what takes place during a chain reaction in a nuclear reactor?

  • an unstable nucleus absorbs a neutron
  • the nucleus undergoes fission & releases 2 or 3 further neutrons
  • these induce more fission, which results in a chain reaction
  • the nuclear reactor controls how much energy is released with control rods
• what is the consequence of an uncontrolled chain reaction?

  • rate of fission events events becomes too high & results in the production of too much energy
  • this leads to a nuclear explosion - how nuclear weapons work