Chapter 3. Radioactivity
Many naturally occurring and man-made isotopes have the property of radioactivity, which is the spontaneous disintegration (decay) of the nucleus with the emission of a particle. The process takes place in minerals of the ground, in fibers of plants, in tissues of animals, and in the air and water, all of which contain traces of radioactive elements.
3.1. Radioactive Decay
Many heavy elements are radioactive. An example is the decay of the main isotope of uranium, in the reaction
The particle released is the α (alpha) particle, which is merely the helium nucleus. The new isotope of thorium is also radioactive, according ...