We assume the reader knows about electrons and how they have negative charges and so on.
We all have played with static electricity and van der Graaff generators. Static electricity is where an object is
either positively (electrons taken away) or negatively (more then normal electrons) charged.
The fun we had with sparks and our hair standing up is static electricity. We know that charges with the same polarity
(++ or --) repels each other and that charges with different polarities (+- or -+) attracts each other.
There is therefore a force between them and this force is summed up in the formula
F = ( q1 x q2 x k ) / r2
Where F is in Newton , q is in coulomb , r is in metres and k is a constant.
We see that no work is done when we have static ( not moving) charges.
Work done is defined as Newton metres or W = F x s where s in metres and F = m x a .
The charge of an electron is -1.6023x10-19 coulomb. So one coulomb of charge is the sum of the charges of 6.25x1018 electrons.
When charges start to move we get an electrical current.
We define current as the tempo at which charges move. So I = dq / dt where q is charge and I is current in ampere.
Therefore 1 ampere = 1 coulomb per second.
So if charge flows past a point at 1 coulomb per second we have a current of 1 ampere.