Physics 4: Atomic Structure + Radioactivity

Physics 4: Atomic Structure + Radioactivity

1. Nuclear Radiation

   • Alpha (α)
     • most ionising power
     • stopped by skin or paper
     • 2 neutrons and 2 protons from a helium nucleus
     • highly likely to be absorbed and cause damage if passing through living cells
   • Beta (β)
     • a high speed electron, ejected from the nucleus as a neutron turns into a proton
     • middle most ionising power
     • stopped by thin piece of metal
   • Gamma (γ)
     • electromagnetic energy/radiation
     • least ionising power
     • stopped by thick metal or concrete

2. Fission + Fusion

   • Fission
     • splitting of unstable nuclei
     • slow moving neutron hits unstable nuclei