nuclear fission

• What is nuclear fission?

  Splitting of a large, unstable nucleus into smaller nuclei
• What is released during nuclear fission?

  Loads of energy
• What are the two ways nuclear fission can occur?

  Spontaneously or by neutron absorption
• How does nuclear energy originate on Earth?

  From nuclear fission
• What is spontaneous fission?

  Unforced fission that happens by itself
• How can neutron absorption cause nuclear fission?

  By making the nucleus less stable
• Why is neutron absorption more common in nuclear reactors than spontaneous fission?

  Spontaneous fission is rare in practice
• What is required to start fission in nuclear reactors?

  Neutrons
• What type of nuclei is used to start nuclear fission?

  Large unstable nuclei
• What happens when a slow-moving neutron impacts a uranium-235 nucleus?

  The nucleus becomes less stable and splits
• Which isotope of uranium is commonly used in nuclear fission?

  Uranium-235
• What are the smaller nuclei produced during nuclear fission called?

  Daughter nuclei
• Besides daughter nuclei, what else is released during the fission of uranium-235?

  Two or three more neutrons and energy
• In what form is energy released during nuclear fission?

  Gamma radiation
• What happens to the neutrons released during nuclear fission?

  They repeat the fission process
• What is a nuclear chain reaction?

  Fission triggers more fission
• What can happen if a nuclear chain reaction is uncontrolled?

  A large release of energy occurs
• Where does an uncontrolled nuclear chain reaction occur?

  In a nuclear bomb
• How is the rate of fission controlled in nuclear reactors?

  Using control rods
• What device is lowered into the reactor to absorb neutrons?

  Control rods
• What is the purpose of control rods in a nuclear reactor?

  To slow down the reaction
• How is the energy released from nuclear fission used in a nuclear power plant?

  To heat water into steam
• What do turbines drive in a nuclear power plant?

  Electricity generators
• What are the pros of nuclear energy?

  • Uranium/plutonium fuel is relatively cheap
  • Produces a large and steady amount of energy
  • Doesn't produce greenhouse gases
• Why is nuclear energy considered "clean" despite not being renewable?

  Because it doesn't produce greenhouse gases
• What are the cons of nuclear energy?

  • Nuclear power plants are very expensive to build
  • Nuclear waste is expensive to dispose of
  • Risk of major disasters
• How is nuclear waste typically disposed of?

  Buried underground in special bunkers
• What is the relative speed of the neutrons fired at the Uranium-235 nuclei?

  Relatively slow moving
• What contributes to public suspicion regarding nuclear energy?

  The risk of major disasters