Alpha, Beta and Gamma Radiation

• What are the three main types of radioactive particles or radiation?

  Alpha particles, beta particles, gamma radiation

  
• Why are some isotopes of elements unstable?

  Due to an imbalance of protons and neutrons
• What process allows a nucleus to become more stable?

  Radioactive decay emitting particles or radiation
• What is an alpha particle?

  A high-energy helium nucleus
• How many protons and neutrons does an alpha particle contain?

  2 protons and 2 neutrons

  
• What is the mass of an alpha particle?

  4u

  
• What is the charge of an alpha particle?

  +2e

  
• Why are alpha particles usually emitted from large nuclei?

  Because they are too large to be stable
• What is the nuclear notation for an alpha particle?

  Helium nucleus notation
• Why are alpha particles the most ionising type of radiation?

  They have the highest charge of +2e
• How many ion pairs do alpha particles produce per cm in air?

  ~10,000 ion pairs per cm
• What does the high ionisation of alpha particles mean for cells?

  They can do more damage to cells
• What is the penetrating power of alpha particles?

  Least penetrating type of radiation

  
• What is the range of alpha particles in air?

  Around 3 to 7 cm
• What is a beta-minus particle?

  A high-energy electron
• Why are beta particles emitted by certain nuclei?

  They have too many neutrons
• What is a beta-plus particle?

  A high-energy positron
• Why are beta-plus particles emitted by certain nuclei?

  They have too many protons
• What is the nuclear notation for beta particles?

  Notation for beta-minus and beta-plus particles

  
• What is the ionising ability of beta particles?

  Moderately ionising type of radiation
• How many ion pairs do beta particles produce per cm in air?

  ~100 ion pairs per cm
• What does the moderate ionisation of beta particles mean for cells?

  They can do some slight damage to cells
• What is the penetrating power of beta particles?

  Moderately penetrating type of radiation

  
• What is the range of beta particles in air?

  Around 20 cm to 3 m
• What are gamma rays?

  A type of high-energy electromagnetic radiation
• Why are gamma rays emitted by certain nuclei?

  To lose some energy
• What is the nuclear notation for gamma radiation?

  Notation for gamma rays
• What is the ionising ability of gamma radiation?

  Least ionising type of radiation
• How many ion pairs do gamma rays produce per cm in air?

  ~1 ion pair per cm
• How does gamma radiation cause damage to cells?

  It can still cause damage, but less than alpha or beta
• Why is gamma radiation widely used for cancer radiotherapy?

  It can cause damage to cells without high ionisation
• What is the penetrating power of gamma radiation?

  Most penetrating type of radiation

  
• What does it mean that gamma radiation has an infinite range?

  It travels the furthest distance in air
• What law does gamma radiation follow?

  Inverse square law
• What are the key differences between alpha, beta, and gamma radiation?

  • Ionising ability:
  • Alpha: Most ionising
  • Beta: Moderately ionising
  • Gamma: Least ionising
  • Penetrating power:
  • Alpha: Least penetrating
  • Beta: Moderately penetrating
  • Gamma: Most penetrating

  
• What happens when radiation collides with an atom?

  It can knock out electrons, ionising the atom

  
• How can the ionising ability of radiation be quantified?

  By the number of ion pairs produced per cm
• What can alpha particles be stopped by?

  A single sheet of paper
• What can beta particles be stopped by?

  A few millimetres of aluminium foil
• What can reduce the intensity of gamma radiation?

  Several metres of concrete or several centimetres of lead