2. Warm up How many paper clips will fit in the glass of water before the water spills over?

3. Hydrogen Bonds: Weak, polar bonds. Form rapidly and break rapidly Example: Between water molecules

4. Hydrogen Bonding explains the following properties of water:   1. Cohesion   2. Adhesion   3. High heat capacity   4. Evaporative cooling   5. Low density of ice   6. The ability of water to dissolve many substances.

5. Water & Solutions  Water = major part of cells 70% of your body – 2/3 of molecules 70% of your body – 2/3 of molecules  Water stores heat efficiently = heats slowly and retains heat longer! Release heat through evaporation.  MAINTAINS HOMEOSTASIS

7. Water & Solutions  Water bonds to itself & other substances  COHESION = attraction between substances of the SAME kind. Hydrogen bonds link molecules together Hydrogen bonds link molecules together Like holding hands Like holding hands Surface tension – prevents surface of water from breaking / stretching Surface tension – prevents surface of water from breaking / stretching

8. The water’s surface tension allows this insect to remain supported.

9. http://www.realeyz.com/photo/macro/photos/leaf_drops.jpg Cohesion Molecules of the same substance are attracted to each other Leads to surface tension and water droplets

10. Water & Solutions  ADHESION = attraction between substances that are DIFFERENT Capillary action = process where water molecules move upward through narrow tube (ex: plant stem) Capillary action = process where water molecules move upward through narrow tube (ex: plant stem) Stronger than downward gravity force.Stronger than downward gravity force.

11. Adhesion Attraction between molecules of different substances Ex: glass and water http://staff.um.edu.mt/rlib1/sm/wpe32.jpg Capillarity Attraction that causes the surface of the liquid to rise when in contact with a solid.

13. Cohesion-Adhesion Theory -As water evaporates from leaves, it tugs on the water molecules below -Cohesion and adhesion pull water up and replace missing water molecules -Water enters the roots by osmosis www.emc.maricopa.edu/.../BioBookPLANTHORM.html Did you ever wonder: How does water move from roots to leaves when a tree doesn’t have a heart to pump the water?

14. Water Dissolves Many Substances  SOLUTION = A mixture in which one or more substances are evenly distributed in another. (Salt Water) EX: Osmosis = movement of material/nutrients between cells. EX: Osmosis = movement of material/nutrients between cells.

15. Like dissolves like  Polar molecules dissolve easily Example: alcohol and water Example: alcohol and water

16. LIKE DISSOLVES LIKE  Non-Polar molecules do NOT dissolve well. EX: OIL and WATER EX: OIL and WATER http://www.worth1000.com/entries/85500/85693bHjg_w.jpg