1. Water

2. Water Basics
Polar: part of a molecule is slightly positive, while another part is slightly negative
Oxygen “hogs” electrons from hydrogen
8 protons: 10 electrons
Negative charge
Hydrogen without electrons
1 proton: 0 electrons
Positive charge
Creates hydrogen bonds where one water sticks to another

3. Red = Oxygen (negative) White = Hydrogen (positive)- - - - - - - - - + + + + + + + + + + + + + + + + + + - - - - - - - - + + + + + + + + + + + + + + + + + + - - - - - - - - - + + + + + + + + + + + + + + + + + +

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

5. Solutions Solution: mixture where 1 substance dissolves in another
2 parts to a solution
1) Solute: substance that dissolves in a solution
Atoms, ions, molecules
2) 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

6. pH Scale pH scale measures the amount of H+ ions
Some molecules release H+ ion when dissolved
H+ ions accumulate (acids)
Some molecules release OH- ions when dissolved
OH- ions accumulate (bases)
pH balance vital to life
Ex: Proteins break apart when outside normal pH

7. 1) Name 4 basic features of water.
2) Which water property explains that one atom is positively charged, while another is negatively charged?
3) How does cohension and adhesion differ?
4) Which is a stronger acid? Substance A with a pH of 5 or substance B with a pH of 3?
5) Which has more H+ ions? Substance A with a pH of 5 or substance B with a pH of 3?
6) Which has more OH- ions? Substance A with a pH of 5 or substance B with a pH of 3?