Momentum of elementary particles
In physics and chemistry, is a spin angular momentum of elementary particles own. In classical mechanics, angular momentum of a body is associated with body rotation around its own center of mass. In quantum mechanics, spin is particularly important for atomic-scale systems such as atoms, protons, and electrons. Such particles have certain characteristics and for other ungraded, intrinsic angular momentum can not be associated with a rotation but only refers to the presence of angular momentum. The concept of elementary particle spin was first proposed by Ralph Kronig, George Uhlenbeck, and Samuel Goudsmit in 1925 as a particle rotating around its axis.
One of the most remarkable discoveries associated with quantum physics is that elementary particles can have nonzero angular momentum. Elementary particles are particles that can not be divided into smaller units, such as photon, electron, and the various quarks. Theoretical and experimental studies have shown that the spin of these particles can not be explained by postulating the idea that they are composed of smaller particles and rotate around a common center of mass, as far as we know, these particles are truly elementary point. Their spin is an intrinsic physical property of these particles, in the same category as mass or electric charge.
