Question: 1) what is the charge on an electron?
Answer: Since the value of the elementary charge is roughly 1.602 x 10-19 coulombs (C), then the charge of the electron is -1.602 x 10-19 C. When expressed in atomic units, the elementary charge takes the value of unity; i.e., e = 1. Thus, the electron's charge can be denoted by -e.