Atomic StructureHow It Works

How It Works: The Mechanism of Each Decay

Part of Radioactive Decay · GCSE GCSE Physics revision

This how it works covers How It Works: The Mechanism of Each Decay within Radioactive Decay for GCSE Physics. Revise Radioactive Decay in Atomic Structure for GCSE Physics with 15 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 14 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 6 of 14

Practice

15 questions

Recall

6 flashcards

⚙️ How It Works: The Mechanism of Each Decay

Alpha decay occurs in very large, heavy nuclei (like uranium). The nucleus is so large that the strong nuclear force cannot hold it together effectively. Emitting an alpha particle (helium-4 nucleus) reduces the size of the nucleus significantly, making the remaining nucleus more stable.

Beta decay occurs when a nucleus has too many neutrons relative to its protons. A neutron is converted into a proton via the weak nuclear force interaction: n → p + e⁻ + antineutrino. The emitted electron (beta particle) and an antineutrino carry away the excess energy.

Gamma emission occurs when a nucleus is in an excited energy state after alpha or beta decay. The nucleus releases this excess energy as a high-energy photon (gamma ray). No change in nucleon numbers occurs — the nucleus simply loses energy and drops to a lower energy state.

Keep building this topic

Read this section alongside the surrounding pages in Radioactive Decay. That gives you the full topic sequence instead of a single isolated revision point.

Nuclear Decay Equations Comparing Alpha, Beta, and Gamma Radiation Unstable Nuclei The Three Types of Radiation

Practice Questions for Radioactive Decay

An alpha particle consists of which particles?

A. 2 protons and 2 neutrons
B. 1 proton and 1 neutron
C. An electron and a positron
D. A proton and an electron

1 markfoundation

Explain why alpha radiation is described as highly ionising but weakly penetrating.

2 marksstandard

Quick Recall Flashcards

Alpha particle is?

2p + 2n (helium nucleus)

Beta particle is?

Fast electron from nucleus

15 questions on Radioactive Decay — practise free

Instant marking, adaptive difficulty, and 6 spaced repetition flashcards. Free until your GCSEs.

Try PrepWise Free

Nuclear Decay Equations

Comparing Alpha, Beta, and Gamma Radiation