Atoms and nuclear radiation

Activity

Measured in becquerel (Bq)

The rate at which a scour e of unstable nuclei decays

Alpha particle

2 neutrons and 2 protons - helium nucleus

Highly ionising

Few centimetres in air

Stopped by paper

Smoke detector- alpha particles are stopped by smoke particles, when alpha particles don’t reach the alarm and it goes off

Beta particle

High speed electron

Ejected from the nucleus when a neutron turns into a proton

Medium ionising

1 meter in air

Stopped by thick aluminium

Gamma ray

Electromagnetic radiation

Low ionising

10s of km in air

Stopped by thick lead

Radioactive decay is

Random

Contamination

the unwanted presence of materials containing radioactive atoms on other materials.

Irradiation

the process of exposing an object to nuclear radiation. The irradiated object does not become radioactive.

How to protect against radiation

Wear gloves

Use tongs to handle any radioactive material