Water makes up about 70% of the mass of your body.
IMPORTANT PROPERTIES of WATER:
1. UNIVERSAL SOLVENT.- water dissolves many substances
2. SURFACE TENSION
A. COHESIVE: water molecules show attractions to each other.
Allows insects to walk on water.
B. ADHESIVE: water molecules show attractions to other substances.
Allows water to climb veins of tall trees.
3. HIGH BOILING POINT: Good insulator-Much energy is needed to
raise or cool body temperature.
4. GOOD COOLANT: Evaporation takes energy from skin, cooling
5. SOLID FORM (ICE) IS LESS DENSE THAN LIQUID FORM, SO ICE FLOATS.
THE ICE CAN THEN ACT AS AN INSULATOR.
6. pH: H2O breaks into H+ (hydrogen ions) and OH- (hydroxide)
H2O ----> H+ + OH-
A. ACID: more H+ ions (pH 0-7)
B. BASE: more OH- ions (pH 7-14)
C. NEUTRAL: H+ = OH- (pH =7)
D. BODY FLUIDS: pH = 7.4