Propetries of Water

Polar molecule

a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive

Dipole

Separation of opposite partial charges across a molecule

Properties of water

• Polarised solvent

• Very high specific heat capacity

• Maximum density at 4°C

• Incompressable

• High surface tension

Polarity

Water is a polar molecule which allows ionic and covalent molecules to dissolve in it. This makes water a good transport medium.

High specific heat capacity

Water does not change temperatures easily which makes large bodies of water a good habitat for aquatic organisms.

Density of water

Water reaches its maximum density at 4°C. As water cools the molecules space out more which decreases its density. This means ice can float and also allows it to melt easily because it is exposed to the most warmth. This allows the water beneath the ice to remain habitable.

Incompressibilty

Water is a liquid which makes it incompressible. This is important for hydraulic mechanisms in organisms.

Surface Tension

Water is cohesive, which allows molecules to stick together. There is also a greater force of attraction between water molecules than between water molecules and the air which means water molecules stick together. This is used in plant transport systems.