|Definition:|| for a particle, electric charge q divided by elementary charge e, thus e, soit c = q/e|
NOTE 1 The charge number of an electrically charged particle can be positive or negative. The charge number of an electrically neutral particle is zero.
NOTE 2 The charge number of a particle may be presented as a superscript to the symbol of that particle, e.g. H+, He++, Al3+, Cl−, S=, N3−.