On Coulomb’s Law

Coulomb’s law states that the magnitude of the electrostatic force of attraction between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them. The force is along the straight line joining them.
If the two charges have the same sign, the electrostatic force between them is repulsive; if they have different signs, the force between them is attractive.