The elementary charge, usually denoted as e or sometimes q, is the electric charge carried by a single proton, or equivalently, the negation (opposite) of the electric charge carried by a single electron. 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 1.6021766208(98)×10?19 coulombs. In the cgs system, e is 4.80320425(10)×10?10 statcoulombs.
The magnitude of the elementary charge was first measured in Robert A. Millikan's noted oil drop experiment in 1909. https://en.wikipedia.org/wiki/Elementary_charge
See Also
charge Figure 16.03 and Figure 16.04 - Electricity as Charged Life and Discharged Death Bearden on Tesla and EM Source Charge Color Charge space charge Atomic Cluster Charge build-up discharge standard model elementary particles