Radioactivity

The whole Universe is built from around a hundred elements such as hydrogen, carbon and silicon. Normally, when we come across these elements and the chemical changes involving them, they are stable and remain the same element throughout. Some elements are naturally unstable and break up and so become different elements. Unstable elements such as these are called radioactive. Radioactive elements decay (break up) into smaller elements. When they do this they emit radiation.

Neutrons and protons form the nuclei of elements. In the nuclei of unstable elements, some of them may break off to leave new elements. Hence the process of radioactive decay causes a rearrangement of the neutrons and protons of the nucleus.

• Background radioactivity
• Types of radioactive emission
• Alpha particle emission
• Beta particle emission
• Gamma radiation
• Half life
• Uses of radioactivity
• Everyday uses
• Radioactive dating