Transmutation of elements
Transmutation of elements, conversion of an atom of one element to an atom of another. Since atoms are identified by their atomic number (number of protons), any change in the number of protons will result in a different element. Atoms may change their number of protons by giving off or taking in atomic particles. Transmutation occurs naturally as a result of radioactive decay. Radioactive atoms are very unstable and give off atomic particles in order to become more stable. With one form of radioactive decay, alpha decay, the atom emits an alpha particle (2 protons and 2 neutrons). With beta decay the atom emits an electron, resulting in the production of a proton and the loss of a neutron. Sometimes, but less often, a positron (a positively charged electron) is emitted, so that a proton is lost and a neutron gained. Artificial transmutation may be accomplished by bombarding atoms with alpha particles so that the atom accepts an extra proton (1 of the 2 is immediately expelled). Transmutation is a by-product of fission (the splitting of nuclei) and fusion (the joining of nuclei).
See also: Radioactivity.