Alpha, Beta and Gamma Particles

• Neutron decay is the emission of a neutron from an unstable nucleus.
• Types of nuclear radiation

  • Alpha particles
  • Beta particles
  • Gamma rays
  • Neutrons
• Gamma rays


  Waves of electromagnetic radiation, weakly ionizing, can penetrate far into materials before being stopped
• Only one or two of an element's isotopes are stable, while the rest are unstable and can undergo radioactive decay
• Beta particles


  Stopped by a thin sheet of aluminium
• Radioactive decay

  Isotopes emit particles to change slightly and become more stable
• Isotopes are different forms of an element with the same number of protons but a different number of neutrons
• Alpha particles


  Stopped by a single sheet of paper
• Beta particles


  Just fast moving electrons, have a charge of -1, emitted when a neutron decays into a proton and an electron, moderately ionizing, penetrate moderately far into materials
• Gamma rays


  Require a thick piece of lead to stop them
• Neutrons can be emitted by a nucleus to increase stability if it contains too many neutrons
• Radioactive materials consist of unstable isotopes that can decay
• Alpha particles

  Consist of two protons and two neutrons, represented by helium's nuclear symbol He, have an overall charge of +2, are easily stopped by collisions, strongly ionizing