This higher tier covers Higher Tier Only: Nuclear Equations in Detail 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 11 of 14 in this topic. This section is most useful once the core foundation idea is secure, because it adds the detail that pushes answers higher.
🎓 Higher Tier Only: Nuclear Equations in Detail
At higher tier, you must be able to complete and balance nuclear equations. The rules are:
- The sum of mass numbers on the left = sum of mass numbers on the right
- The sum of atomic numbers on the left = sum of atomic numbers on the right
Example — Alpha decay of radon-220:
²²⁰₈₆Rn → ?_?X + ⁴₂α
Mass number: 220 = ? + 4 → ? = 216
Atomic number: 86 = ? + 2 → ? = 84 → element is Polonium (Po)
Answer: ²²⁰₈₆Rn → ²¹⁶₈₄Po + ⁴₂α
Beta decay example: In ⁰₋₁β, the "−1" atomic number counts in the balance.
Practice questions for Radioactive Decay
An alpha particle consists of which particles?
Explain why alpha radiation is described as highly ionising but weakly penetrating.