Quote from Wikipedia:
Another way to view surface tension is in terms of energy. A molecule in contact with a neighbor is in a lower state of energy than if it were alone (not in contact with a neighbor).
As I understand the above statement, is that if two molecules (of the same liquid) are separated, then they have a larger energy as when they are together. Can you please explain a bit why this happens? Is there a physical/chemical reason? Thank you.