Question

Why electrons revolve around atoms? and what is charge produced by it?

Answer 1

Answer to charge
Electron negative
Nucleus positive

Answer why they revolve

Electrons were once thought to orbit a nucleus much as planets orbit the sun. That picture has since been obliterated by modern quantum mechanics. But since quantum mechanics confounds even seasoned physicists, the image persists as a useful analogy.
“Like gravity acting on planets, an electromagnetic force attracts the orbiting electron to the nucleus.” That is why they revolve
Classical physicists wondered that the electron didn't run out of energy.

In a crystal clear way

A positive nucleus attracting a negative electron made sense. But why isn't the electron falling to the nucleus then?

Neils Bohr postulated that this was because electron was rotating around the nucleus and the centrifugal force offseted the electromagnetic force.