Alpha, beta and gamma radiation

• What are isotopes?

  Different forms of an element with varying neutrons
• How do isotopes of an element differ?

  By the number of neutrons they contain
• What does it mean for an isotope to be unstable?

  It can undergo radioactive decay
• What is radioactive decay?

  Emission of particles to become stable
• What does it mean if a material is radioactive?

  It consists of unstable isotopes that decay
• What are the four types of nuclear radiation?

  • Alpha particles
  • Beta particles
  • Gamma rays
  • Neutrons
• What are alpha particles made of?

  Two protons and two neutrons
• What is the nuclear symbol for alpha particles?

  He
• What is the charge of alpha particles?

  Two plus
• Why can alpha particles not penetrate far into materials?

  They are relatively large and easily stopped
• How far can alpha particles travel in air?

  A few centimeters
• What can stop alpha particles?

  A single sheet of paper
• What does it mean for alpha particles to be strongly ionizing?

  They can easily knock off electrons from atoms
• What are beta particles?

  Electrons emitted from decaying neutrons
• What is the charge of beta particles?

  Negative one
• How are beta particles emitted?

  From a neutron decaying into a proton and electron
• How far can beta particles penetrate materials?

  Moderately far, several meters of air
• What can stop beta particles?

  A thin sheet of aluminium
• What are gamma rays?

  Waves of electromagnetic radiation
• Why are gamma rays emitted?

  To rid the nucleus of extra energy
• How do gamma rays interact with materials?

  They pass straight through without colliding
• What can stop gamma rays?

  Thick sheets of lead or concrete
• What happens when a nucleus emits a neutron?

  It increases stability by reducing neutrons
• What are the key differences between alpha, beta, and gamma radiation?

  • Alpha:
  • Made of 2 protons and 2 neutrons
  • Charge: +2
  • Stopped by: paper
  • Strongly ionizing
  • Beta:
  • Electrons
  • Charge: -1
  • Stopped by: aluminium
  • Moderately ionizing
  • Gamma:
  • Electromagnetic waves
  • Charge: 0
  • Stopped by: lead/concrete
  • Weakly ionizing
• What is the overall charge of alpha particles?

  Two plus
• What is the mass of beta particles?

  Virtually no mass
• How do alpha particles compare to beta particles in terms of size?

  Alpha particles are relatively large
• How does the ionizing ability of gamma rays compare to alpha particles?

  Gamma rays are weakly ionizing
• What is the purpose of emitting a neutron from a nucleus?

  To increase stability