1. Chapter 4
Water, Waves, and Tides

2. Today: I’ll give you 20 minutes to take your quiz.
When you are finished, you’ll have a worksheet to work on.

3. Key Concepts
The polar nature of water accounts for many of its physical properties.
Seawater contains a number of salts, the most abundant being sodium chloride.
Salts are constantly being added to and removed from the oceans.
The exchange of energy between oceans and the atmosphere produces winds that drive ocean currents and weather patterns.

4. Key Concepts
The density of seawater is mainly determined by temperature and salinity.
Vertical mixing of seawater carries oxygen to the deep and nutrients to the surface.
Waves are the result of forces acting on the surface of the water.
The gravitational pull of the moon and the sun on the oceans produces tides.

5. Table 4-1 Physical Properties of Water

6. Nature of Water Marine organisms are ______________water by mass.
Terrestrial organisms are approximately ___________water by mass!
Physical properties of water
excellent _____________
high boiling point and freezing point
______________ in its liquid form than in its solid form
supports marine organisms through buoyancy
provides a medium for chemical reactions necessary for life

7. Nature of Water Structure of a water molecule
2 ___ atoms bonded to 1 ____ atom
________________ - different parts of the molecule have different electrical charges: the oxygen atom carries a slight negative charge; the hydrogen atoms carry a slight positive charge

8. Figure 4-1 (a) Water Molecules.

9. Nature of Water Freezing point and boiling point
polar water molecules tend to come together forming ____________________ with one another
high _____________reflects energy needed to overcome attractive forces of hydrogen bonds
relative high freezing point (0oC) of water is a result of less energy needed to fix molecules into position to form solid

10. Figure 4-1 (b) Water Molecules.

11. Figure 4-1 (c) Water Molecules.

12. Nature of Water Water as a solvent
polar nature keeps solute’s_____________in solution
water cannot dissolve ________________ molecules, e.g., oil and petroleum products

13. Figure 4-1 (d) Water Molecules.

14. (a) Polar nature of water molecule Hydrogen bond
(b) Hydrogen bonding of water molecules due to its polarity
Salt
(c) Structure of water molecules in a solid state (ice)
Stepped Art
(d) Salt crystals dissolving in water
Fig. 4-1, p. 70

15. Nature of Water Cohesion, adhesion, and capillary action
hydrogen bonds cause water molecules to be ________________, i.e., stick together, accounting for high surface tension
__________________ - attraction of water to surfaces of objects that carry electrical charges, making them “wet”
adhesion also accounts for water’s ________________- the ability of water to rise in narrow spaces

16. Figure 4-3 Adhesion And Capillary Action.

17. Nature of Water ____________________(Thermal capacity) Water and light
water has a high specific heat (amount of heat energy needed to raise 1 g 1o C) due to hydrogen bonds
ocean can maintain relatively constant temperature
Water and light
much light _______________into the atmosphere
different _________________ (colors) of light penetrate to different depths

18. Nature of Water Chemical properties of water
acids release_________atoms in water
bases bind H ions and remove them from solution
pH scale measures __________________________.
pH of pure water is 7, considered neutral
ocean’s pH is slightly ____________________(average 8) owing to bicarbonate and carbonate ions
organisms’ internal and external pH affect life processes such as metabolism and growth

19. Figure 4-4 pH Scale.

20. Increasing alkalinity
pH paper
Increasing acidity 1 2 3 4 5 6
Gastric juice
Vinegar
Urine
Rain water
Neutral
Human saliva 7
Blood
Increasing alkalinity 8 9 10 11 12 13 14
Egg white
Seawater
Great Salt Lake
Liquid soap
Oven cleaner
Stepped Art
pH scale
Fig. 4-4, p. 72