Key learning points

1. Radioactive particles can emit radiation in the form of particles or gamma radiation.
2. Ionising radiation forces electrons from atoms, leaving an atom with a positive charge called an ion.
3. Alpha particles are more ionising than beta or gamma because they have a bigger charge and stronger electric field.

Keywords

• Radioactive particle - a particle that can decay and emit nuclear radiation

• Radiation - emitted by a radioactive nucleus when it decays

• Ionisation - the removal of one or more outer electrons from an atom

• Alpha particle - a particle of radiation made from two protons and two neutrons, with a relative charge of +2

• Beta particle - a particle of radiation made of an electron emitted at high speed from an unstable nucleus

Common misconception