1. Properties of Water

2. Water covers 2/3 of Earth 97% Saltwater oceans 2.4% Ice (polar caps and glaciers) 0.6% Surface water (lakes and streams)

4. The Human body is made of ~80% water. To function properly, the body requires between one and seven liters of water per day to avoid dehydration; the precise amount depends on the level of activity, temperature, humidity, and other factors. Most of this is ingested through foods or beverages other than drinking straight water.

5. Properties of Water Remember…. Water has 2 hydrogen atoms and one oxygen atom Remember…. Water has 2 hydrogen atoms and one oxygen atom H 2 O O H H _ + + Hydrogen bond (+) H H (–) O Water is polar ….

6. Properties of Water cohesion adhesion High specific heat density pH

7. Cohesion The natural attraction of a water molecule to other water molecule is called cohesion.

9. Adhesion The attraction of a water molecule to another polar molecule is adhesion. water droplets on a spider’s web (polar surface).

10. Properties associated with polarity/ adhesion, cohesion Capillary Action Surface Tension Transpiration

11. Capillary Action

12. Surface Tension At the surface of the drop of water, water does not attract to the air….. Surface tension

13. Jesus Lizard

14. Transpiration

15. Properties of Water cohesion adhesion High specific heat density pH

16. Density

18. Why is “ice floats” important??  if ice sank….. o eventually all ponds, lakes, and even ocean would freeze solid o during summer, only upper few inches would thaw  surface ice insulates water below o allowing life to survive the winter

19. Properties of Water cohesion adhesion High specific heat density pH

22. An example is the more moderate climate of a coastal location compared to one far inland.

23. Properties of Water cohesion adhesion High specific heat density pH

25. pH 7 pH 14 pH 0 neutral More acidic…more H ions More basic…more OH ions water Most biological fluids have a pH b/w 6 and 8 …. But stomach can reach a pH of 2

26. Properties of Water cohesion adhesion High specific heat density pH