1. How Do The Properties of Water Support Life on Earth?

2. Polar Molecules Polar Molecules share electrons unevenly.
The side with the higher electron affinity will have a negative charge.
The side with the lower electron affinity will have a positive charge.

3. Water: Universal Solvent
Because water acts like a polar magnet, it can dissolve other polar substances.
This property allows water to be a medium for chemical reactions.
Water is also a transport medium. Molecules and ions are transported by blood.

4. Molecule

5. Hydrogen Bonding
Opposite charges attract, so the negative end of one water molecule will tend to orient itself so as to be close to the positive end of another molecule that happens to be nearby.

6. Hydrogen Bonding

7. Cohesion: Produces Surface Tension
Cohesion: Water attracted to water
Surface tension allows small organisms to survive on the surface and provide food for larger organisms.

8. Adhesion: Produces Capillary Action
Adhesion: Water attracted to something else
Capillary Action: Water will rise up thin tubes against the force of gravity.
Capillary action allows water to be drawn up from roots to stems & leaves against the force of gravity.

10. Expansion on Freezing
Since water expands on freezing, ice is less dense than liquid water. The ice insulates life below.

12. High Specific Heat: Maintain Homeostasis
Specific Heat is the energy required to raise 1g of water 1 ◦C.
Water has a high specific heat. It requires a lot of energy to change the temperature of water.
The high specific heat of water helps organisms maintain homeostasis and resist sudden temperature changes.

14. How Do The Properties of Water Support Life on Earth?
Property How Life is Supported