The force of attraction between two atoms?

There are two such forces:

1) The electrical force occurs between two charged objects. When this force occurs between to point like objects, the following equation holds:

F=Kq1q2/d^2, where

F is the electric force

K is a constant = 8.988*10^9

q1 is the charge of one object

q2 is the charge of the second object

d is the distance between the objects

2) The gravitational force occurs between two masses. If these two objects are point like the following equation holds:

F=Gmm/d^2, where

F is the gravitational force

G is a constant = 6.673*10^-11

m1 is the mass of one object

m2 is the mass of the second object

d is the distance between the objects

you may notice two things about these fundamental forces:

1) The electrical force is much stronger that the gravitational force. This is why the force of gravity is neglected when dealing with electric forces between subatomic particles, ions, and molecules.

2) These two forces are very analogous. both forces are proportional to the product of a property of two objects (mass or charge) and to the inverse of the square of the distance between those particles.