Basic electrical cell, c 1990s.
© Science Museum / Science & Society Picture Library
A basic electrical cell consists of copper and zinc plates immersed in sulphuric acid. When the plates are connected by a conducting wire, hydrogen gas is emitted from the copper plate, which loses electrons to the sulphuric acid making it become positively charged. This charge causes zinc to disolve from the zinc plate, leaving behind electrons which make the plate negative. These electrons move through the wire from the zinc plate toward the copper one, thus creating an electric current.