1. “Properties of Water”

2. Water has a very simple atomic structure.
This structure consists of two hydrogen (H) atoms bonded
to one oxygen (O) atom. The unique way in which the hydrogen atoms are attached to the oxygen atom causes
one side of the molecule to have a negative charge and
the area in the opposite direction to have a positive charge.
The hydrogen side of the water molecule has a slight positive charge. The oxygen side of the water molecule has
a slight negative charge.
This polarity causes molecules of water
to be attracted to each other forming strong molecular bonds.

3. HYDROGEN BONDS PROPERTIES of water due to POLARITY cohesive behavior
resists changes in temperature
high heat of vaporization
expands when it freezes
universal solvent

4. polar molecule a molecule that has electrically charged areas
molecule with a slightly
positive end and a slightly
negative end as a result of
electrons being shared unequally forming an attraction that holds the molecules together

5. between water molecules to form drops and remain
cohesion
attractive force
between water molecules
that allows water
to form drops and remain
a liquid at room temperatures 

6. between water molecules
adhesion               
attractive force
between water molecules
and other solid substances

7. the water runs along the glass and does not fall straight.
Caused by adhesion
the water runs along the glass and does not fall straight.

8. capillary action the combined force of attraction
between water molecules and with molecules of other surrounding materials
process that moves water through narrow tubes or small porous spaces 

9. capillary action

10. Capillary action is related to
the adhesive properties of water.
You can see capillary action 'in action' by placing a straw into a glass of water.
The water 'climbs' up the straw.
What is happening is that the water molecules are attracted to the straw molecules. When one water molecule moves closer to the straw molecules the other water molecules (which are cohesively attracted to that water molecule) also move up into the straw.
Capillary action is limited by gravity and the size of the tube. The thinner the tube or straw, the higher up capillary action
will pull the water.

11. EXAMPLES: capillary action
adhesion
+ cohesion
= capillary action
water taken up by roots
All due to hydrogen bonding!

12. the tightness across the surface of water
surface tension               
the tightness across the surface of water
due to the cohesive properties of water that is caused by the polar molecules pulling on one another

13. Water behaves as if covered by an invisible skin.
Water has a greater surface tension than most other liquids because hydrogen bonds among surface water molecules resist stretching or breaking the surface.
Water behaves as if covered by an invisible skin.
Some animals can stand, walk, or run on water without breaking the surface.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

14. buoyancy             
the upward force on an object produced by the surrounding fluid (liquid or gas) in which it is fully or partially immersed 
the net upward force is equal to the weight of the fluid displaced by the object

15. universal solvent Water is considered to be the universal solvent.
More substances will dissolve
in water than any other liquid. 
This includes other
polar substances
(such as sugar)
and ionic compounds
(such as salt).  

16. specific heat               
amount of heat energy required to raise the temperature of 1 kg of a substance by 1 degree Celsius

17. Water’s high specific heat ensures slow temperature changes.
Water can absorb large amounts of heat energy before it begins to get hot.

18. Water’s high specific heat ensures slow temperature changes.
Water releases heat energy slowly when it cools.

19. Water is Less Dense as a Solid
Ice is less dense as a solid than as a liquid (ice floats)
Liquid water has hydrogen bonds that are constantly being broken and reformed.
Frozen water forms a crystal-like lattice whereby molecules are set at fixed distances. 1

20. Water is Less Dense as a Solid
Which is ice and which is water? 1

21. Water is Less Dense as a Solid
Ice 1

22. Acids, Bases and pH H2O  H+ + OH-
One water molecule in 550 million naturally dissociates into a Hydrogen Ion (H+) and a Hydroxide Ion (OH-)
Hydrogen Ion Hydroxide Ion
Acid Base
H2O  H+ + OH-

23. The pH Scale Indicates the concentration of H+ ions Ranges from 0 – 14
pH of 7 is neutral
pH 0 up to 7 is acid … H+
pH above 7 – 14 is basic… OH-
Each pH unit represents a factor of 10X change in concentration
pH 3 is 10 x 10 x 10 (1000) stronger than a pH of 6

24. Acids
Strong Acids have a pH of 1-3
Produce lots of H+ ions

25. Bases Strong Bases have a pH of 11 to 14
Contain lots of OH-ions and fewer H+ ions

26. Buffers
Weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH (neutralization).
Produced naturally by the body to maintain homeostasis
Weak Acid
Weak Base