The charge on an electron is -1 elementary charge, denoted as e-. The elementary charge is the fundamental unit of electric charge in the International System of Units (SI). It is approximately equal to -1.602 x 10^-19 coulombs (C).
The charge of an electron is negative, while the charge of a proton is positive, with the same magnitude. In an atom, electrons are negatively charged particles that orbit around the positively charged nucleus, which consists of protons (positively charged) and neutrons (electrically neutral). The electron's charge is essential for understanding the behavior of atoms and their interactions with other particles in various physical and chemical processes.
It is worth noting that the charge on an electron is considered a fundamental constant in physics, and it is an important quantity in various fields of study, including electromagnetism, quantum mechanics, and particle physics.