Cohesion: The property of like molecules (of the same substance) to stick to each other due to mutual attraction.
Adhesion: The property of different molecules or surfaces to cling to each other.
Surface Tension: the result of cohesive forces between adjacent molecules.
Density: Liquid water has a density of 1. Most substances are more dense when they are solids than when they are liquid. However, water becomes less dense when it goes from a liquid to a solid. That is why ice floats on water.