3. Water Basics Polar: part of the molecule is slightly positive… other part slightly negative – Oxygen (-) – Hydrogen (+) Hydrogen Bond: Positive Hydrogen attracted to negative oxygen

5. Water Properties Energy needed to break H bonds High specific heat: Water resists temp changes – Helps to maintain a constant body temp Cohesion: water molecules attracted to other water molecules (see bug picture) Adhesion: water sticks to other molecules

6. Solutions Solution: mixture where 1 substance dissolves in another Solute: substance that dissolves in a solution – Atoms, ions, molecules Solvent: substance in which the solute is dissolve – Usually water Ex: Human blood – Plasma (water) is the solvent – Carbs, proteins, sugars, etc… is the solute

7. pH Scale pH scale measures the amount of H+ ions Some compounds release H+ ion when dissolved H+ ions accumulate (acids) More H+ ions = more acidic pH balance vital to life