<Tr> <Th> Definition: </Th> <Td> Charge of a proton </Td> </Tr> <Tr> <Th> Symbol </Th> <Td> e or sometimes q </Td> </Tr> <Tr> <Th> Value in coulombs: </Th> <Td> 6981160217662079999 ♠ 1.602 176 6208 (98) × 10 C </Td> </Tr> <P> The elementary charge, usually denoted as e or sometimes q, is the electric charge carried by a single proton, or equivalently, the magnitude of the electric charge carried by a single electron, which has charge − e . This elementary charge is a fundamental physical constant . To avoid confusion over its sign, e is sometimes called the elementary positive charge . This charge has a measured value of approximately 6981160217662079999 ♠ 1.602 176 6208 (98) × 10 coulombs, or in cgs units, 6990480320425000000 ♠ 4.803 204 25 (10) × 10 statcoulombs . </P>

Who showed that the charge on any particle is a multiple of the charge on an electron