Isotopes and Nuclear Radiation

• What are isotopes of an element?

  Atoms with the same protons, different neutrons
• What is the mass number of an atom?

  Total number of protons and neutrons
• Why do all atoms of each element have a set number of protons?

  Protons define the identity of the element
• What is the atomic number of an atom?

  Number of protons in the nucleus
• What is radioactive decay?

  Unstable nucleus decays into another element
• What is ionising radiation?

  Radiation that creates positive ions
• What are the three types of ionising radiation?

  Alpha (α), beta (β), and gamma (γ)
• What are the characteristics of alpha radiation?

  • Consists of 2 protons and 2 neutrons
  • Absorbed by a sheet of paper
  • Range in air: few centimetres
  • Ionising power: strong
  • Example of use: smoke detectors
• What are the characteristics of beta radiation?

  • Consists of an electron from the nucleus
  • Absorbed by a sheet of aluminium
  • Range in air: few metres
  • Ionising power: moderate
  • Example of use: material thickness testing
• What are the characteristics of gamma radiation?

  • Consists of electromagnetic radiation from the nucleus
  • Absorbed by thick sheets of lead
  • Range in air: longer distances
  • Ionising power: weak
  • Example of use: medical tracers
• How does mass change during alpha decay?

  Mass decreases by 4
• How does charge change during alpha decay?

  Charge decreases by 2
• How does mass change during beta decay?

  Mass stays the same
• How does charge change during beta decay?

  Charge increases by 1
• What happens to a neutron during beta decay?

  It turns into a proton
• What changes occur in mass and atomic numbers during nuclear decay?

  • Alpha decay:
  • Mass decreases by 4
  • Charge decreases by 2
  • Beta decay:
  • Mass stays the same
  • Charge increases by 1