The Chemistry of Fundamental Particles and Nuclei

During recent years there has been a great increase in our knowledge of the world. Atoms have been found to consist of electrons and nuclei, and the atomic nuclei have been found to consist of protons and neutrons. Moreover, in addition to the electron, the proton, and the neutron, many other particles have been discovered. 

The field of science dealing with the nature and the reactions of these particles is developing very rapidly at the present time. Work in this field of science has been carried out largely by physicists, but the reactions by means of which the particles are created, converted into others, and destroyed are in a general way similar to chemical reactions, and we may be justified in considering the study of these reactions and the properties of the particles themselves as constituting the field of the chemistry of particles. 

At the present time about 200 particles are known, of which 34 may be classed as fundamental. This number includes 6 (the photon, the graviton, two neutrinos, and two antineutrinos) that move only with the speed of light, and 28 that move only at speeds less than the speed of light. In accordance with the theory of relativity, the particles that move only at the speed of light have zero rest-mass, whereas the others have finite rest-mass. 

---