2. A Lesson From The Mathematics & Science Center The Mathematics & Science Center

3. Did you know— -About 75% of the Earth’s surface is covered by water? -Most of that water is in the oceans! -The amount of salt in different oceans’ water determines the types of plants and animals that live there. -Ocean water with lots of salt is heavier or denser and moves to the bottom through currents. -Oceanographers use the term salinity to refer to the amount of salt in the water.

4. Refraction of Light Through Water Can light bend?

5. Refraction of Light Through Glass Light

6. REFRACTION Light slows down and bends as it passes through substances of different densities.

7. Refraction Lab

8. Which is saltier? The Atlantic Ocean or……..

9. The Chesapeake Bay or…

10. The James River?

11. Atlantic Ocean Chesapeake Bay Map of Virginia

12. Fresh water from rain, and rivers and streams. Salinity of the Bay depends on the amount of rainfall. Most fresh water comes into Bay from northern & western rivers, causing Bay water to be less salty in north and west areas. Bay receives salt water from Atlantic Ocean, causing Bay water to be more salty closer to ocean. Differences in Salinity

13. Freshwater Habitats Ponds, Lakes, Streams, Rivers Virginia’s aquatic habitats contain water of varying salinities.

14. Brackish Water Habitats Streams, Rivers, Marshes

15. Bay and Full Ocean Water Habitats Chesapeake Bay, Atlantic Ocean

16. Salinity Refractometer

17. Raise the plastic cover plate. Using an eyedropper, place 2-3 drops of water on the blue glass surface. Lower the cover plate so that the water spreads across the surface. Make sure that the cover is flat. Using a Salinity Refractometer

18. - Hold the refractometer downward at about a 45 degree angle. -Face toward a light source and look through the eyepiece. -View the scale.

19. Refractometer Scale With Distilled Water

20. Refractometer Scales With Saline Water

21. Hands-on Lab Determining the Salinity of Water Sample 1 Sample 2 Sample 3