Explain,
A system consists of 55 electrons and 43 protons.

Electrons and protons have the same size charge but the opposite sign in their charge. That charge is negative 1.6 x 10-19 Coulombs for electrons and positive for protons. The total charge of a system depends on which particle is present in an excess amount. Since the electrons outnumber the protons by 12, then the total charge is:

(12) x (-1.6 x 10-19 Coulombs) = - 1.92 x 10-20 Coulombs

Explanation: