A certain amount of charge q, which is flowing through a cross section of a conductor is equal to the number of electrons n, crossing this section, multiplied by the elementary charge. If this elementary charge is indicated as e we have: q= ne.
The amount of electric current at a certain cross section is determined by the charge and so by the number of electrons n, passing a specific cross section during a certain time period Δt. The electric current is indicated as I.
I = ne/Δt = q/Δt.
This unit of the electric current is called "amps", abbreviated A, in honour of the French physicist André-Marie Ampère (1775-1836). A current of 1 A corresponds to a flow of 1 Coulomb = 6,2 10 18 electrons per second through a cross section.