Properties of Water Chapter 2 Pages 18-47

1. Properties of WaterChapter 2Pages 18-47 Marine Science Ms. Flick

2. Vocab • Basins • Renewable resource • Nonrenewable resource • Overfishing • Sublimation • Freezing points • Melting point • Boiling point • Variables • Independent variable • Dependent variable • Solvent • Solute • Solution • Solubility • Atom • Neutrons • Protons • Hydrogen bonding • Cohesion

3. Vocab Continued. • Hydrogen bonding • Cohesion • Surface tension • Salinity • Vaporization • Freezing • Condensation • Brackish • Estuaries • Neutral buoyancy

4. Our Oceans • The ocean covers approximately 71% of Earth’s surface • Our planet’s ocean can be divided into four oceans: • The Pacific • The Atlantic • The Indian • The Arctic • Basins-large water covered areas between continents; commonly referred to as oceans • Earth’s ocean contains 97% of the water on Earth • That leaves only 3% of the planet’s water as fresh as opposed to salt • 2/3 of that freshwater is contained in ice in glaciers and sea ice caps in Earth’s polar regions

6. Ocean’s Renewability • The ocean is important for all living things and influences many of Earth’s processes • The ocean is a resource that replenishes itself naturally over relatively short periods of time • Renewable resource • Some resources, such as natural gas and minerals, are exhausted faster than they are naturally replaced • Nonrenewable resources • Just because the ocean is considered a renewable resource doesn’t mean everything in it is • Overfishing-humans extract fish at rates faster than they can reproduce making the food source no longer renewable

8. Activity 1 Procedure • Prepare two beakers-1 w/ cold water, 1 w/ warm water • Measure and record the temperature of each • Place 15 drops of blue food coloring into the cold water and stir • What will happen if cold water (blue) from a pipette is added to the warm water carefully down the side of the beaker? Write down your hypothesis-if/then statement • Add droppers full of the cold blue water down the inside wall of the warm water beaker • Drop some on one side-then the opposite side • Note: the dropper tip should be placed immediately under the surface of the water • Write down your observations.

9. Activity 2 • Prepare 2 beakers-1 w/ warm water and 1 w/ ice cubes • Measure the temperature of each beaker’s contents and record • Place several ice cubes in the water

10. Discussion • How can you explain our observations of Activity 1? • What are the ice cubes made of? • In Activity 1 the cold water stayed on the bottom. If the ice is colder than the water would you expect it to float on the water? • What issues would their be in nature if ice did not float on water?

11. Investigation 1:Freezing, Melting, and Boiling Follow the directions in your textbook on pages 23-26 to complete this investigation. Write down your findings on your own sheet of paper.

12. Investigation 2:Surface Tension Follow the directions in your textbook on pages 26-27 to complete this investigation. Write down your findings on your own sheet of paper.

13. Investigation 3:Floating and Sinking Follow the directions in your textbook on pages 28-29 to complete this investigation. Write down your findings on your own sheet of paper.

14. Investigation 4:Solutions Follow the directions in your textbook on pages 30-31 to complete this investigation. Write down your findings on your own sheet of paper.

15. Atoms • Atom-the most basic particle of a unique element that has the properties of that element • Neutrons-no electrical charge • Protons-a +1 or a positive 1 charge • Around the dense nucleus of each unique atom is a cloud of tiny, negatively charged electrons • Look at figure 2.16-hydrogen atom • Look at figure 2.17-oxygen atom • Hydrogen and oxygen combine to make a water molecule

16. Water Molecules • Look at figure 2.19-water molecules • Hydrogen bonding-the attraction between water molecules • Cohesion-the property of water making it attracted to other molecules of water via hydrogen bonding • It is cohesion that allows water to form drops • Surface tension-the attraction between molecules at a liquid’s surface

17. Salinity • Salinity-the measure of dissolved salts in water • Distilled water has no salinity • Water is considered fresh if it contains 1 part per thousand or less of salts • The average salinity of the ocean is 35 parts per thousand (35% salt)

18. Ocean Water • Ocean water carries a lot of minerals • The minerals come from: • Land: freshwater in streams and rivers contains salts and flows into the ocean • Inside the Earth: volcanoes, vents, and other processes at the seafloor spew minerals from below Earth’s crust • Atmosphere: carried by wind and deposited into the ocean

19. Phase Changes • Vaporization- liquid to gas • Freezing- liquid to solid • Condensation- gas to liquid • Pure water boils at 100 degrees C • 212 degrees F • Pure water freezes at 0 degrees C • 32 degrees F • Salt water boils and becomes a gas at a slightly higher temperature than freshwater • Salt water freezes at a slightly lower temperature

20. Freshwater and Saltwater Meet • Brackish-water that is somewhere between salt and fresh • Margrove forests and salt marshes • Estuaries-where rivers meet the sea • Nurseries of the sea; provide home for many species of marine life • Plants and animals living here can tolerate wide ranges in salinity b/c their always changing

21. Neutral Buoyancy • Some organisms float on top of the ocean • Others live near its bottom • Others make their homes throughout the water column • Organisms have features that assist them with floating and sinking or moving up and down-neutral buoyancy