Explains how radiation is produced and the characteristics of alpha, beta, and gamma radiation.

Overview of radioactivity, the process in which particles are emitted from nuclei as a result of nuclear instability.

A lovely biographical piece about Ernest Rutherford. A number of personal notes, along with extensive information about the physics work he did. Nice quote at the end.

Counting alpha particles was tedious and time-consuming work, until Hans Geiger came up with a device that did the job automatically.

Explains what is meant by the half-life of a radioactive element and how it is calculated.