Radioactivity
Radioactivity was discovered by Henri Becquerel. He found that uranium salts had emitted invisible radiation. There are three main types of radiation: Alpha, Beta and Gamma. These are all classed as ionising radiation because they can ionise atoms by removing some of their electrons leaving positive ions.
To see this ionisation you can use a cloud chamber which shows the liquid condensing onto the ions leaving tracks in the air.
Qwerty123uiop - Own work, CC BY-SA 4.0
## Electric and Magnetic FieldsWhen charged particles pass through an electric or magnetic field they are deflected. The amount of deflection depends on the charge and mass of the particle. Alpha particles are large and heavy so they are deflected the least, while beta particles are small and light so they are deflected the most. Gamma rays are not charged so they are not deflected at all. This allows us to identify the type of radiation by passing it through the fields.
See also
References
- Radioactivity - Wikipedia
WEB - A Level Physics OCR (Pages 484-486)
BOOK