Benedykt Grela
Benedykt Grela voted up Ray Dart's answer

If you are talking about "nuclear" atomic energy, then there are two main sorts.

Fission energy: This is where the natural tendency for some radioactive elements (usually isotopes of Uranium, although other metals have been used, notably recently, thorium) to decay, releasing energy whilst doing so. In controlled conditions the product of decay (a free neutron) … Read more