Identical particles fermions, which do not share quantum states as described by the Pauli exclusion principle. Examples of bosons are photons, gluons, phonons, helium-4 nuclei and all mesons. Examples of fermions are electrons, neutrinos, quarks, protons, neutrons, and helium-3 nuclei. The fact that particles can be identical has important consequences in statistical mechanics. Calculations in statistical mechanics rely on probabilistic arguments, which are sensitive to whether or not the objects being studied are identical. As a result, identical particles exhibit markedly different statistical behaviour from distinguishable particles. For example, the indistinguishability of particles has been proposed as a solution to Gibbs' mixing
Elementary charge known elementary particles, including quarks, have charges that are integer multiples of "e". Therefore, one can say that the "quantum of charge" is "e". In this case, one says that the "elementary charge" is three times as large as the "quantum of charge". On the other hand, all "isolatable" particles have charges that are integer multiples of "e". (Quarks cannot be isolated: they only exist in collective states like protons that have total charges that are integer multiples of "e".) Therefore, one can say that the "quantum of charge" is "e", with the proviso that quarks are not to be