Types of Radiation

This lesson covers the three main types of nuclear radiation — alpha ($\alpha$α), beta ($\beta$β) and gamma ($\gamma$γ) — including their nature, penetrating power, ionising ability and behaviour in electric and magnetic fields. This is a core part of the Radioactivity section of the Edexcel GCSE Combined Science specification (1SC0).

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Why Do Nuclei Emit Radiation?

Some atomic nuclei are unstable — they have too many or too few neutrons relative to protons. To become more stable, the nucleus emits radiation in a process called radioactive decay. This is a random and spontaneous process:

• Random — it is impossible to predict when a particular nucleus will decay.
• Spontaneous — it is not triggered by external conditions (temperature, pressure, chemical reactions).

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The Three Types of Radiation