Charles Agustin Coulomb
his name is used as SI unit for charge, defined in terms of electrical current, which is the rate of flow of charge. The reason is that one can make precise measurement of the current flowing in wire, whereas the charge on the body tend to leak away.
The coulomb is a very large amount of charge. A typical charge acquired by rubbed body is 10power(-8) coulomb, or 10 micro coulomb, whereas light bolt may transfer as much as 20 C between the earth and cloud. When a body is charged by rubbing, only about 1 in 100,000 of the surface atoms gains or loses an electron. Even for very highly charged body, only about one in 500 of the surface atoms have a net charge. Electrical effect arise from a very small imbalance in the usual neutral state of matter.
