Wonders of Water Miller and Levine 2-2

The magic is in the molecule! Water molecules are polar. Means what? Water molecules are unevenly charged because the part of the molecule (near the oxygen) is more negatively charged and the part near the hydrogen (more positively charged).

Draw it!

Draw in more water molecules to demonstrate hydrogen bonding.

Cohesion, Adhesion, and Surface tension Cohesion - water molecules are attracted to each other (hydrogen bonding) Adhesion - water molecules are attracted to other molecules Capillary Action (wicking) - cohesion and adhesion Surface tension - water molecules line up on surfaces (drops, ponds, etc.)

Why are these properties essential to living things? Capillary Action Surface tension

High Specific Heat It takes a great deal of energy to raise water temperature. Why is this property essential to living things?

High Heat of Vaporization It takes a great deal of energy for water to phase change from a liquid to a gas. Why is this essential to living things?

Evaporative Cooling As a liquid evaporates the molecules closest to the surface vaporize. The molecules that remain are cooler and the surface is cooler. Why is this essential to living things?

Ice is less dense than water. When frozen, the water molecules spread out more (longer hydrogen bonds). Ice is about 9% less dense than water. Why is this essential to living things?

Water is the universal solvent. Most substances (gases and solids) can be dissolved in water. Why is this essential to living things?

Water has a neutral pH. Water has a pH of 7. Why is this essential to living things?

Examples

Examples