Radioactivity

Syllabus tag: KCSE | Chemistry | Form 4 | Topic 24 Radioactivity

Lesson objectives

By the end of this topic, you should be able to:

• Explain radioactive decay and describe alpha, beta and gamma emissions.
• Write and balance nuclear equations.
• Define half-life and carry out calculations.
• Describe fission, fusion, uses, hazards and safety precautions.

Summary

Radioactivity is the spontaneous disintegration of unstable nuclei. Alpha is a helium nucleus, beta an electron from the nucleus, gamma an electromagnetic wave. In nuclear equations mass numbers and atomic numbers must balance. Half-life is constant for an isotope and unaffected by chemical or physical conditions.