What Causes Surface Tension.

• Liquids exist because of attractive forces between molecules. The forces in liquids are not as strong as in solids, in which molecules, atoms or ions are held rigidly in place, but they are much stronger than in gases because gas molecules experience little or no intermolecular attraction. Molecules in the center of a liquid are pulled from all sides by their neighbors. However, at the surface these molecules are only pulled inwards or laterally. There is nothing to pull them outwards. This lateral force is surface tension.