Physics 2 - Ionising Radiation

Ionising Radiation

Alpha Particles

• An alpha particle is two neutroms and two protons - the same as a helium nucleus.
• They are relatively big and heavy and slow moving.
• They therefore don't penetrate very far into materials and are stopped quickly, even when travelling through air.
• Because of their size they are stongly ionising, which just means they can bass into a lot of atoms and knock electrons off them before they slow down, which creats lots of ions.
• It can be stopped by skin, paper and 5cm of air.

Beta Particles

• Beta particles are in-between alpha amd gamma particles in terms of their properties.
• They move quite fast and are quite small (they're electrons).
• They penetrate moderatly into materials before colliding, have a long range in air, and are moderatly…