1. The Extraordinary
Properties of Water

2. WATER is important for all living things
Average person ~~ 60-70% water
Human brain ~~ 90%
Cells are about 70-95% water

3. Water
A water molecule (H2O), is made up of three atoms: one oxygen and two hydrogen. O 1

4. - + Polar Molecules Because of the location of electrons in molecules,
some molecules have an
_________ pattern of
____________________
More ___ on one side;
More ___ on the other
EX: water
UNEVEN
ELECTRIC CHARGE + -

5. WHAT HOLDS MOLECULES TOGETHER?
Molecules are _____________by the ________ between ______________ regions of nearby molecules = _____________________
HELD TOGETHER
ATTRACTION
OPPOSITELY CHARGED
VAN DER WAALS FORCES

6. HYDROGEN BONDS
Bonds that form between the _________ charged _____________
in one molecule and a
__________ charged _________
in a nearby molecule are called
_____________________
POSITIVELY
HYDROGEN ATOM
NEGATIVELY
ATOM
HYDROGEN BONDS
EX: water molecules
are held together
by Hydrogen bonds

7. Hydrogen Bonds
one hydrogen bond is weak , but many hydrogen bonds are strong
CLICK LINK BELOW FOR AN ANIMATION FOR BONDING

8. Hydrogen bonds
weak
form, break, and reform with great frequency
Each bond only lasts a few trillionths of a second
However, hydrogen bonding is what gives water it’s essential properties…

9. Each water molecule can form hydrogen bonds with up to four neighbors

10. Water At sea level, pure water boils at 100 °C and freezes at 0 °C.
The boiling temperature of water decreases at higher elevations (lower atmospheric pressure).
For this reason, an egg will take longer to boil at higher altitudes. 1

11. Properties of Water
What are they? 1

12. Properties of Water
Cohesion 1

13. Properties of Water Cohesion Adhesion
This is a great notes interaction! It will help you remember and not get them confused! 1

14. Properties of Water
Cohesion
Adhesion
High Specific Heat 1

15. Properties of Water Cohesion Adhesion High Specific Heat
High Heat of Vaporization 1

16. Properties of Water Cohesion Adhesion High Specific Heat
High Heat of Vaporization
Less Dense as a Solid 1

17. Cohesion Attraction between particles of the same substance itself
- why water is attracted to
itself
Results in: Surface tension (a measure of the strength of water’s surface)
surface film on water
-allows insects to walk on the surface of water 1

18. Water Properties
Polarity
Cohesiveness
Adhesiveness
Surface Tension

21. Basilisk lizard: The Jesus Lizard

22. Adhesion Attraction between two different substances.
- water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton. . 1

23. Copyright Pearson Prentice Hall23
Copyright Pearson Prentice Hall

24. Capillary action-water molecules will “tow” each other along when in a thin glass tube i.e. transpiration process which plants and trees remove water from the soil, and paper towels soak up water.

26. High Specific Heat
Amount of heat needed to raise or lower 1g of a substance 1° C.
Water resists temperature change, both for heating and cooling.
Water can absorb or release large amounts of heat energy with little change in actual temperature. 1

27. High Heat of Vaporization
Amount of energy to convert 1g or a substance from a liquid to a gas
In order for water to evaporate, hydrogen bonds must be broken. As water evaporates, it removes a lot of heat with it. 1

28. Water has a high heat capacity
Heat capacity (specific heat) is the quantity of heat required to change the temperature of a substance by 1 degree
Water can store a lot of heat!
It changes temperature very slowly

29. “Water vapor forms a kind of global ‘blanket’ which helps to keep the earth warm. Heat radiated from the sun-warmed surface of the earth is
absorbed and held
by the vapor.” 1

30. 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

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

32. Water is Less Dense as a Solid
Ice 1

33. Homeostasis
Ability to maintain a steady state despite changing conditions
Water is important to this process because:
a. Makes a good insulator
b. Resists temperature change
c. Universal solvent
d. Coolant
e. Ice protects against temperature extremes 4

34. WATER IS THE UNIVERSAL SOLVENT

35. IMPORTANCE OF WATER FOR ORGANISMS
Cells are about 70-95% water
90% of cytoplasm is water
92% of blood plasma is water
97% of tissue fluid and lymph is water  

36. Takes part in metabolic reactions:
photosynthesis: water is a raw material in the light stage
Respiration: aerobic respiration produces water
Anabolism: produced when macromolecules are made
Catabolism: water is used to break the bonds in macromolecules
REMEMBER:
METABOLISM = ANABOLISM + CATABOLISM

37. Movement of materials through cell membranes:
Diffusion
Osmosis
Active transport

38. Turgor pressure plays an important role in the support of plants
Loss of turgor pressure:
Plant wilts
turgor pressure restored
Plant supported