Nuclear Fission and Fusion

• What is nuclear fission?

  The splitting of large, unstable nuclei
• What is produced alongside smaller nuclei during nuclear fission?

  Spare neutrons are emitted
• Give an example of a fissionable isotope.

  Uranium - 235
• What usually needs to happen to induce fission?

  An unstable nucleus must absorb a neutron
• What is spontaneous fission?

  Fission without neutron absorption
• What is emitted in a fission reaction alongside two smaller nuclei?

  Two or three neutrons
• What form of energy do all fission products have?

  Kinetic energy
• What takes place during a chain reaction in a nuclear reactor?

  An unstable nucleus absorbs a neutron
• What is the consequence of an uncontrolled chain reaction?

  It can lead to a nuclear explosion
• What are the three main components of the core of a nuclear reactor?

  • Fuel rods
  • Control rods
  • Moderator
• What is the role of the moderator in a nuclear reactor?

  To slow down neutrons for absorption
• How is the chain reaction in a fission reactor kept under control?

  By moving control rods up and down
• What term describes nuclei that can undergo fission with slow neutrons?

  Fissile Nuclei
• What is nuclear fusion?

  The joining of two light nuclei
• Name two isotopes of hydrogen used in nuclear fusion.

  Deuterium and Tritium
• Which releases more energy, nuclear fission or nuclear fusion?

  Nuclear fusion
• Why is generating energy through nuclear fusion difficult?

  It requires very high temperatures
• Why is nuclear fusion not currently viable for energy production on Earth?

  Energy required exceeds energy produced