Question

What is the charge of a body whose proton is 4 x 10 15 and 5 x 10 15 ?

Answer 1

The charge of one proton is

$$e = 1.6\times 10^{-19}C$$

If a body contains $N_1 = 4\times 10^{15}$ or $N_2 = 5\times 10^{15}$ uncompensated protons, then its charge is (respectively):

$$Q_1 = eN_1 = 1.6\times 10^{-19}C\cdot 4\times 10^{15} = 6.4\times 10^{-4}C\\ Q_2 = eN_2 = 1.6\times 10^{-19}C\cdot 5\times 10^{15} = 8\times 10^{-4}C$$

Answer.

$Q_1 = 6.4\times 10^{-4}C\\ Q_2 = 8\times 10^{-4}C$