radioactvity

• • (Beta minus)$\beta^-$ is a fast moving electron.
  • (Beta plus)$\beta^+$is a fast moving positron.
• What is ionsing radiation?

  High-energy radiation that can remove electrons from atoms, which damages body cells causing mutation. E.g. Cancer
• A beta particle is emitted when a neutron turns into a proton in the nucleus.
• An alpha particle is the same as a helium nucleus (2 neutron, 2 protons).
• Gamma is an electromagnetic wave.
• The three types of radioactive decay are:

  • Alpha ($\alpha$)
  • Beta ($\beta$)
  • Gamma ($\gamma$)
• Alpha radiation is the most ionising out of the three.
• Gamma is the least ionising.
• The atom was believed to be indivisible, before the discovery of the electron.
• In alpha decay, the atomic number (number of protons) decreases by two.
• In beta minus decay, the atomic number increases since there is once more proton.
• What is the unit for radioactive activity?

  Becquerel (Bq)