Electric charge

Electric charge is the property of matter that makes it feel the electromagnetic force. It comes in two signs, is conserved absolutely, and — as far as every experiment can tell — only ever appears in whole multiples of the elementary charge e.

The elementary charge

quantity	value
e	1.602 176 634 × 10⁻¹⁹ C (exact, by SI definition since 2019)
charge of the Electron	−1 e
charge of the proton	+1 e
charge of the Positron	+1 e

Rules it always follows

• Conservation — the total charge of an isolated system never changes. No exception has ever been seen.
• Quantization — free particles carry whole multiples of e. (Quarks carry ⅓ fractions, but never travel alone.)
• Two signs — like charges repel, opposite charges attract; the force follows Coulomb's law.