Alpha , Beta and Gamma

• Alpha particles


  • Large, can travel around 5 cm in air before colliding with air particles and stopping
• Beta particles


  • Can travel further than alpha particles, around 15 cm in air before stopping
• Gamma radiation


  • Can travel much further than alpha or beta particles, several meters in air before stopping
• Penetrating power


  Tells us what type of material is required to stop each form of radiation
• Penetrating power of alpha particles


  • Relatively easy to stop, stopped by a single sheet of paper
• Penetrating power of beta particles

  • Harder to stop than alpha, need a few millimeters of aluminium to stop
• Penetrating power of gamma radiation

  • Hardest to stop, need several centimeters of lead to stop
• Ionizing power


  Ability of radiation to cause atoms to lose electrons and form ions
• Ionizing power of alpha particles


  • Very strongly ionizing, can produce a lot of ions when colliding with material
• Ionizing power of beta particles

  • Quite strongly ionizing, but not as ionizing as alpha particles
• Ionizing power of gamma radiation


  • Only weakly ionizing