4.4.2.1 Radiation

Spec reference: 4.4.2 (subtopic).

What you need to know

• radiation. Ionising
• radiation is radiation that can knock
• electrons off atoms. Just how ionising this
• radiation is, depends on how readily it can
• do that.
• Beta
• Beta radiation is a fast moving electron that
• can be stopped by a piece of aluminium. Beta

Self-assessment (checklist)

• I can describe what is meant by radioactive decay.
• I can describe what is meant by the activity of an
• I can describe what is meant by the count-rate of an
• I can describe four types of nuclear radiation.
• I can describe the penetration of alpha, beta and gamma
• I can describe the range of alpha, beta and gamma
• I can describe the ionising power of alpha, beta and
• I can evaluate the best sources of radiation to use in a

Key steps (method)

• Identify what the question is testing and use the correct equation/definition.
• Show substitutions and units clearly.

Common mistakes

• Unit conversions, rearranging errors, or quoting a law without applying it.