Properties of Water

1. Polarity - Polar molecules have a positive (+) and a negative (-) side. In water, the Hydrogen is positive and the Oxygen is negative.

2. Cohesion - The positive hydrogens are attracted to the negative oxygen of a neighboring water molecule. The molecules are held together by these Hydrogen bonds.

Examples of Cohesion: The shape of raindrops Water beading up on a newly polished car The convex surface of water when a container is filled to nearly overflowing Surface tension – an organism can walk on water if it doesn’t break the hydrogen bonds holding the water molecules together. (water strider, basilisk)

3. Adhesion - Because water molecules are polar they stick to other substances. Ex: water sticks to the side of the graduated cylinder forming a meniscus

The volume is read from the bottom of the meniscus.

4. Capillarity - This is how water gets from the roots to the leaves. Water moves up narrow tubes by a combination of adhesion and cohesion. This is how water gets from the roots to the leaves.