A neutron (see also baryon) is a fundamental component of a nucleus. Neutrons, discovered by James Chadwick in 1935 (Nobel Prize in physics), have no charge and are about 1838 times more massive than electrons.

See also Neutron Activation, Neutron Activation Analysis, Neutron Radiation and Neutron Capture.

Nuclear charge number is the number of protons in the nucleus of an atom.

See also Mass Number, Ordinal Number.

A nucleon is a proton or a neutron - part of the nucleus.

In the periodic systems of elements the ordinal number sorts elements by their nuclear charge (their protons).

See also Nucleus, Proton and Mass Number.

Nuclear reaction in which a proton enters the nucleus and a neutron is emitted.