Alpha (α)
- Made up of 2 protons and 2 neutron
- Strongly ionizing
- Low penetrating power – can be stopped by paper or several cm of air.
Beta (β)
- Fast moving electron
- Moderately ionizing
- Moderately penetrating – can be stopped by 1 m of air or several cm of aluminium
- Emitted when a neutron turns into a proton and releases an electron
Gamma (γ)
- Very high frequency electromagnetic waves
- Weekly ionizing
- Strongly penetrating – can be stopped by several cm of lead or 1 m of concrete