Radiation
- this happens when a nucleus is unstable
Alpha radiation
- made up of 2 protons and 2 neutrons
- mass number: 4
- proton number: 2
- hint: same as Helium
Beta radiation
- losing an electron
- a proton turns into a neutron
- mass number: 0
- proton number: -1
Penetration
- alpha: least penetrating
- beta:
- gamma: most penetrating
Contamination
- occurs when radioactive nuclei enter on or into another object
Irradiation
- occurs when an object is exposed to radiation (from outside)
- the object does not become radioacative
Use of irradiation
- e.g. gamma rays
- used in sterlisation
- can kill bacteria
- slow down decay e.g. for food
Half life
- the time taken for the number of nuclei of an isotope in a sample to half.
