Radioactivity

Syllabus tag: KCSE | Physics | Form 4 | Topic 39 Radioactivity

Lesson objectives

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

• Explain radioactive decay and describe alpha, beta and gamma radiation.
• Write and balance nuclear equations.
• Define half-life and solve problems on decay.
• Describe detectors, uses, dangers and precautions, and nuclear energy.

Summary

Radioactivity is the spontaneous disintegration of unstable nuclei with the emission of alpha, beta or gamma radiation. Alpha is a helium nucleus, beta an electron, and gamma an electromagnetic wave. Half-life is the time for half the nuclei to decay, and it is constant for a given isotope.