1. Solids, liquids and gases can conduct electricity if there is a sufficient number of free electrons or ions.
2. In an insulator, electrons are too tightly fixed by chemical compounds
to be able to move, and the material normally and does not conduct
electricity.
3. Opposite charges thus experience the attracting forces, while like charges are pushed aside.
4.
The force is proportional to the product of the charges and inversely
proportional to the square of the distance between them, this ratio
is known as Coulomb's law.