the attractive or repulsive interaction between two charged particles
is given by Coulomb's law, which states that the force between the two particles is proportional to the product of their charges and inversely proportional to the square of the distance between them:
F = k(q1*q2)/r^2
where F is the force between the particles, q1 and q2 are their charges, r is the distance between them, and k is a constant known as Coulomb's constant. If the charges are of the same sign, the force is repulsive, while if they are of opposite signs, the force is attractive.