How do molecules interact with each other?

Each atom contains negatively and positively charged particles (electrons and protons). When there are the same number of electrons as there are protons, these charges cancel each other, but if there is an imbalance, then the atom will carry an electrical charge.
The positioning of atoms in a molecule can give it polarity. If two positively charged atoms are next to each other in a molecule, this region may have a slight positive charge, while elsewhere the charge may be slightly negative.