1. Water Amazing Stuff!

2. 1. Water is a Polar Molecule! Like the earth has poles, so a water molecule has “poles”. It has positive and negative poles. This is called polarity.

3. 2. Water is the “Universal Solvent” Because water molecules have a positive side and a negative side, any atom with a positive or negative charge can bond with it. In fact, water is a universal solvent. This means water can combine with other chemicals to form a solution.

4. 3. Adhesion: Water Sticks to Things! The polarity of water causes its positive side to stick to negative things and its negative side stick to positive things.Water is actively attracted to other molecules.

5. 4. Cohesion: Water sticks to itself! Because water is polar, other molecules of water are attracted to water molecules! This makes water stick together. Soap Kills Cohesion!

6. 5. Cohesion Causes Surface Tension Because water is cohesive, water molecules make a skin on the top of water. Thus water bugs and paper clips can float on water even though they should (and will) sink.

7. Surface Tension makes paper clips float!

8. But is different from Buoyancy which is called Archimedes Principle Buoyancy is the upward force that keeps things afloat. The net upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body. This force enables the object to float or at least seem lighter.

9. 6. The Density Anomoly: Solid water forms a crystal. Solids are more dense than liquids. Liquids are more dense than gases… but not for water. Water forms a crystal structure which makes ice (solid water) less dense than liquid water.

10. Density of Water Most dense at 4 o C Contracts until 4 o C Expands from 4 o C to 0 o C The density of water: 1.Prevents water from freezing from the bottom up. 2.Ice forms on the surface first—the freezing of the water releases heat to the water below creating insulation. 3.Makes transition between season less abrupt.

11. The amount of heat that a substance can hold is called Specific Heat. Three-fourths of the earth is covered by water. The water serves as a large heat sink responsible for: 6. Water holds a lot of Heat! 1.Prevention of temperature fluctuations that are outside the range suitable for life. 2.Coastal areas having a mild climate 3.A stable marine environment

13. 7. Water Moderates Temperatures on Earth Celsius Scale at Sea Level 100 o CWater boils 37 o CHuman body temperature 23 o CRoom temperature 0oC0oCWater freezes Water stabilizes air temperatures by absorbing heat from warmer air and releasing heat to cooler air. Water can absorb or release relatively large amounts of heat with only a slight change in its own temperature.

14. http://fizyka.phys.put.poznan.pl/~pieransk/Physics%20Around%20Us/Surface%20tension%2002.jpg http://www.polytechconsultants.com/images/surftens.jpg http://quest.nasa.gov/space/teachers/microgravity/image/66.gif http://gallery.hd.org/_tn/std/natural-science/_more2006/_more01/meniscus-on-water-surface-tension-supporting-steel- paperclip-in-drinking-glass-tumbler-beaker-6-AJHD.jpg http://gallery.hd.org/_tn/std/natural-science/_more2006/_more01/meniscus-on-water-surface-tension-supporting-steel- paperclip-in-drinking-glass-tumbler-beaker-6-AJHD.jpg http://www.diracdelta.co.uk/science/source/a/r/archimedes%20principle/image004.jpg