The nuclei of the atoms in some elements are unstable and emit radiation. The radiation can be of three types - alpha radiation, beta radiation and gamma radiation.

For example, the half-life of Iodine 131 is eight days, but for Uranium 238, which is present in varying amounts all over the world, it is 4.5 billion years. Potassium 40, the main source of ...

All types of radiation become less intense as they travel further away from the radioactive material. This is because the particles or rays become more spread out. The thicker the substance ...

The first module provides a basic understanding about radiation - what it is, where it comes from and the different types of radiation amd how people can protect themselves from its adverse effects.