Water is Polar: because Oxygen is more electronegative than Hydrogen.

Emergent Properties: Because of cohesion, adhesion, and surface tension, water has some special characteristics.

Hydrogen Bond:
A bond/attraction between the negative part of a molecule and the positive part, where hydrogen is involved.

Cohesion:
When two of the SAME molecules form a hydrogen stick together, Ex. Water in a glass.

Adhesion:
When two DIFFERENT molecules form a hydrogen stick together, Ex. Amino Acid + Water.

Surface Tension:
Increased hydrogen bonds on the surface of the water, which can make it stay together, and solid-ish.

Water is almost a Universal Solvent:
The adhesive properties of water make this possible and are very important for organisms, for getting nutrients.
Charged molecules dissolve in water very easily, like Na+ and K+

Ice(solid) is LESS dense than water(liquid):
This is possible because of the unique cohesive properties, and it is important because ice can form on the surface of the water, and still leave liquid water underneath for organisms to consume.
Water also expands as it freezes.
Water is the densest at -4 degrees Celsius.

Water has a HIGH heat capacity:
This is because of the unique cohesive properties, and is important, so that water doesn’t suddenly change temperature, which would kill much fish.

Capillary Action:
Water goes into small spaces/capillaries, like straw or tube, because of the adhesive and cohesive abilities, as the water will bond with the glass(adhesion), and then it will build a stairwell with itself(cohesion).
Important for plants to suck up water with roots.

Meniscus:
Water bonds to the sides of a tube in a U-like formation.