# Why do two molecules of an element attract each other?

I was thinking about molecular attraction and a question suddenly struck in my mind which is 'Why do two molecule of an element attract each other?'

The answer is easy when we discuss about compound materials. The molecules of a compound have dipoles that can attract each other. But what happens about elements? The molecules of an element don't have dipoles.

After so many attempts, I thought there are only two particles in those molecules that can attract each other — Neucleus and Electron. But also there works repulsive forces between the electrons and between the neucleus of two molecules. It seems like the repulsion is stronger attraction.

So how the attraction force get stronger than the repulsion force so that two molecules of an element attract each other?

• this qualitative answer of mine may help physics.stackexchange.com/questions/262280/… . There are various types of bonding. Apr 27 at 8:59
• I didn't find here something what I am looking for. Apr 27 at 9:05
• Have you studied quantum mechanics and its probabilistic nature ? Apr 27 at 10:41
• I have not studied quantum probabilistic nature yet. Apr 27 at 11:34
• When you say molecular attraction do you mean the attraction between two different molecules of $O_2$ or do you mean the attraction between two atoms within a single molecule of $O_2$? Just naming $O_2$ as an example Apr 27 at 11:39

Van der Waals interaction causes mutual attraction of many if not all of the following elemental molecules H$$_2$$, Na$$_2$$, K$$_2$$, noble gas atomic molecules, S$$_8$$, O$$_3$$, O$$_8$$, F$$_2$$, Cl$$_2$$, buckyballs, carbon nanotubes, cyclocarbons. O$$_2$$ is magnetic, so here probably magnetic attraction dominates.