Nucleon

The term nucleon indicates in a generic way the components of the Atomic nucleus, i.e. the Proton S and the Neutron S which are both of the Baryon S. the number of nucleons per atom is generally noted “has” , and called “Mass number”

Until in the years 1960, the nucleons were regarded as elementary particles. It is known now that they are particles made up of Quark S and of Gluon S. the properties of these particles are controls mainly by the strong Interaction. The Proton is lightest of the Baryon S, and it is the only one which is stable. More exactly, measurements which were made show that the proton has one lifespan higher than 10³⁰ years, which brings a strong constraint on the speculative theories which try to go beyond the standard model. On its side, the Neutron has one average lifespan from approximately 1/4 of hour) and disintegrates by weak Interaction in Proton, electron and electronic Antineutrino. The proton and the Neutron form a doublet of Isospin I=1/2.