Biochemical Techniques and Instrumentation (1+2)

3.1.2. Radioactive decay

Alpha particles are formed as a result of the decay of relatively heavy radioisotopes. They consist of two neutrons and two protons, bound together. Americium 241 (Am-241) is a example and commonly found in household smoke detectors.

In beta decay, a neutron gets converted to a proton, emitting a beta particle. Beta particle is identical to an ordinary electron. Carbon-14 (C-14) is a radioisotope of carbon, which undergoes beta decay and is used to establish the age of ancient artifacts known as "carbon dating".

Gamma rays are emitted, if a nucleus still has excess energy following decay and the emission of other particles. They are electromagnetic in nature and also called "photons" with a discrete and unique energy. They are not physical particles, but their interactions with matter assigned them particle-like properties. They are used to identify different radioisotopes.