Fission and fusion

• what is nuclear fission

  • the splitting of a large unstable nucleus into two smaller nuclei
  • uranium and platonium are used as fuels in in power stations
• what are the products of nuclear fission

  • 2 smaller nuclei
  • two or three neutrons
  • gamma rays
• what is the energy transfer in nuclear fission

  nuclear potential energy -> kinetic energy
• what is spontaneous fission

  • nuclei undergoes fission without additional energy being supplied
• what is induced fission

  • the unstable nucleus must absorb a neutron to undergo fission
  • a neutron is supplied as without it, fission and energy production would be slow
• what is a nuclear fission chain reaction?

  • When 2 or 3 neutrons are produced at speed, they go on to be absorbed by another nucleus which triggers more fission
  • a chain reaction is started
• what is a controlled chain reaction?

  • In a nuclear reactor, a chain reaction is crucial to keep the reactor functioning
  • the number of free neutrons must be kept constant to ensure the reactor dosen't produce a dangerous amoutn of energy
  • control rods control the rate tht energy is produced by controlling the number of free neutrons in the reactor
• what are control rods

  • absorb neutrons
• what is an uncontrolled chain reaction

  • this is what a nucelar weapon uses
  • produces a dangerously huge amount of energy in a short time
• what is nuclear fusion?

  • 2 light nuclei join to form a heavier nucleus
  • requires extremely high temps - only in space