1. PROPERTIES OF WATER

2. Water: A Most Important Substance
Life as we know it would not exist without water.
Compared to other compounds and minerals, water has extraordinarily unique properties.
It does things (things that support life) that other substances don’t.

3. Structure of Water 2H2 + O2  2H2O H2O What makes water?
What does this mean?
Simply put, hydrogen (H) and oxygen (O) combine to make water (H2O)
A single water molecule is a compound made of two hydrogens and one oxygen.
H2O

4. Structure of Water + + + +
Water is polar, meaning one side is positively (+) charged and the other side is negative (-). + + + + ▬ ▬
Because Oxygen is bigger, it “hogs” more electrons.
Thus, the Oxygen side of water tends to be negative (-), and the Hydrogen side positive (+).

5. Water is a Polar Molecule -has oppositely charged ends
Water consists of one oxygen atom bound to two hydrogen atoms by two single covalent bonds.
Oxygen has unpaired & paired electrons which gives it a slightly negative charge while Hydrogen has no unpaired electrons and shares all others with Oxygen
Leaves molecule with positively and negative charged ends (like a magnet)

6. WATER’S POLARITY AND HYDROGEN BONDS

7. Water’s Properties Cohesion Adhesion Capillary Action
Solid water (ice) is less dense than liquid
Solvent

8. Cohesion Water clings to polar molecules through hydrogen bonding
Cohesion refers to attraction to other water molecules.
responsible for surface tension
a measure of the force necessary to stretch or break the surface of a liquid

9. COHESIVE PROPERTY

11. Adhesion Adhesion refers to attraction to other substances.
Water is adhesive to any substance with which it can form hydrogen bonds.

12. ADHESIVE PROPERTY

13. water evaporates from leaves = transpiration
Capillary action
water evaporates from leaves = transpiration
All thanks to hydrogen bonding!
adhesion, cohesion and capillary action
water taken up by roots

14. Water Cells are about 70-95% water.
Three-quarters of Earth’s surface is submerged in water.
Water is the only common substance to exist in all three physical states of matter
solid, liquid and gas

15. STATES OF WATER

16. WATER AS A GAS

17. WATER AS A LIQUID

18. WATER AS A SOLID

19. Solid water (ice) is less dense than liquid
Ice is less dense than water: the molecules are spread out to their maximum distance
Density = mass/volume
same mass but a larger volume

20. SOLUTIONS: Water is the “universal solvent” Solute: Substance that is dissolved (Salt NaCl) Solvent: Substance in which the solute dissolves (Water) Polarity makes water a great solvent!!!!!!!!!!!!!!!!!!!!!!!!!!
What other solutions could be made using water?

21. pH Scale

22. THE END