The idea of atoms as ultimate indivisible pieces of matter goes back to the time of ancient Greeks. The first evidence for energetic processes going inside atoms had come in 1895 accidentally by Wilhelm Rontgen while he was experimenting with cathode rays. The discovery of x rays stimulated other people to search for other forms of radiation from atoms and in 1896, Heneri Becquerel discovered that atoms of uranium produce another kind of radiation. Two years later Ernest Rutherford showed that there are actually two kinds of radiation which he called alpha rays and beta rays. A third form of radiation, gamma rays was discovered later. The emitted rays revealed the secret of the nucleus.

In this unit you are going to learn about the properties of these rays, the secret of the nucleus and ways of harvesting energy from the nucleus.