IGCSE Physics: nuclear decay equations is one of the most searched topics because radioactivity appears in almost every Physics paper. You need to identify alpha, beta and gamma decay, write balanced equations (mass number and atomic number conserved), and understand half-life and safety.

Types of Decay and Equations

• Alpha: Nucleus emits α (helium nucleus); mass number −4, atomic number −2. e.g. (^{226}{88}\text{Ra} \rightarrow ^{222}{86}\text{Rn} + ^4_2\alpha)
• Beta minus: Neutron → proton + electron; mass number same, atomic number +1. e.g. (^{14}_6\text{C} \rightarrow ^{14}7\text{N} + ^0{-1}\beta)
• Beta plus (if in syllabus): Proton → neutron + positron; atomic number −1.
• Gamma: No change in mass or atomic number; nucleus loses energy only.

Always balance top (mass number) and bottom (atomic number) on both sides.

Half-Life and Safety

• Half-life: Time for half the nuclei to decay; used in calculations (e.g. activity after n half-lives).
• Safety: Distance, shielding, time; alpha/beta/gamma have different penetrating power and range.

Tutopiya’s Physics tutors can help you master nuclear equations and half-life calculations.

Exam-Style Questions and Common Mistakes

You may be asked to identify the type of decay (alpha, beta, gamma), write a balanced equation, or calculate activity or amount left after a number of half-lives. Always balance mass number and atomic number on both sides. Common mistakes: Wrong change in atomic number for beta; forgetting to include the particle emitted; half-life calculation errors (after n half-lives, fraction left = (1/2)^n). For safety questions, mention distance, shielding, and time.

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