1. Water Chemistry

2. Component of Life Life would not exist without water
Only known life to us
Life began in water
Cells are 70-95% water
Earth is 75% covered with water
Exists as solid, liquid, and a gas naturlly on Earth

3. Property #1: Cohesion
Hydrogen bonds that hold water molecules together
Water breaks bonds easily and reforms easily-water has structure
Important: High surface tension = hard to break surface layer of water. Animals can use to stand, walk, run

4. Cohesion

5. Property #2: Adhesion Clinging of one substance to another
Water clings to surface of vessels in plant. Overcomes gravity.
Cohesion keeps water molecules together moving upward

6. #3 High Specific Heat
Requires high amount of heat (energy) to be absorbed/lost to change 1 g of water by 1 degree Celsius
Can absorb/release high amounts of heat
Moderates Earth’s climate-75% of Earth is water
Makes Earth habitable

7. #4 High Heat of Vaporization
Large amount of heat(energy) needed to change 1g of liquid water to gas
Hottest molecules lost (highest amt of energy), cooler ones left behind
Moderates climate. Warm air circulated to cold poles.
Evaporative cooling-plants and animals prevent overheating

8. #5 Solid Water Floats!
No other element in solid form floats in same liquid form – Unique to water
Water in sold form (ice) is less dense than liquid form (water)
Ice floats!
Lakes, ponds, oceans still habitable when top freezes – Ice insulates water

9. #6 Water is Neutral pH value of 6-7.5 Not acidic or basic
Changes to the pH can damage or cause death to organisms, Ex. Acid rain
Your body has ways to deal with acidic/basic conditions – Buffers – neutralizes