Cambridge Encyclopedia » Cambridge Encyclopedia Vol. 23

electron - Classification, Properties and behavior, In practice, In theory, History

charge negative particle beta

A fundamental particle, denoted e?, where the minus sign indicates that the charge is negative; charge of ?1·602 × 10?19C; mass 9·110 × 10?31 kg or 0·511 MeV, approximately 1/1836 that of the proton; spin ½ fermion; stable against decay; no known size, assumed point-like; no known substructure; a carrier of negative charge in matter, including electrical currents in conductors. Electrons together with the positively-charged nucleus form atoms. They were discovered by J J Thomson in 1897 through studying cathode rays (now called electron beams) in electric and magnetic fields. The charge was determined by Robert Millikan in 1913. Wave-like properties are exhibited in electron diffraction. The electron is associated with weak nuclear force, as in radioactive beta decay, where the beta particle is the electron.

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or