1. Water

2. Fun Facts you should know
Water is unique in that it is the only natural substance that is found in all three physical states—liquid, solid, and gas—at the temperatures normally found on Earth.
Water freezes at 32° Fahrenheit (F) and boils at 212°F
What temperatures would that be in Celcius?
Air pressure affects the boiling point of water, which is why it takes longer to boil and egg at Denver, Colorado than at the beach

3. Bonding
Water is formed when one oxygen forms 2 single covalent bonds with 2 hydrogen atoms.
This is a polar molecule. So the oxygen is slightly negative and each hydrogen is slightly positive
Each H2O can form 4 Hydrogen bonds

4. Melting and Boiling points
Are higher than expected for the covalent bond because of the hydrogen bonds.
This is called a high specific heat--it absorbs a lot of heat before it begins to get hot.
This is why water is valuable to industries and in your car's radiator as a coolant.
It also helps regulate the rate at which air changes temperature near bodies of H2O, works daily and seasonally
It also helps explain how we stay at 98o body temp

5. Sweating
In addition to high specific heat, it takes a lot of energy for water to change phases.
A lot of energy has to be taken from your body to allow sweat to evaporate into the air—this makes us feel cooler (unless the air is to humid to absorb the sweat)

6. Water is neutral Pure water has exactly equal numbers of + and - .
It therefore has a pH of 7 and will not conduct electricity.
Unfortunately pure water is hard to find.
Water in nature has dissolved substances and does conduct electricity.

7. Water is sticky Hydrogen bonds make water stick to other
waters in cohesion, which causes droplets, surface tension and beading.
It also allows for water to stick to other things in adhesion. Examples Water droplets on pine needle and the meniscus in a glass graduated cylinder.

8. Surface tension
Twice as much hydrogen bonding occurs between the waters at the top and that creates:
a “skin” that can float objects,
allow insects to walk on water,
allows bubbles to be circular and resist popping,
Explains why cold water doesn’t wet materials as easily as hot water
And explains why some fabrics are
water resistant until touched.

9. Capillary action
Due to a combination of adhesion and cohesion, water will flow up a narrow tube (against gravity)
This allows for
Plants moving water from roots to leaves
Your eyes to remove tears in small numbers
Good Pens to not leak ink
And the absorbency of paper towels

10. Types of mixtures
When two substances are mixed without a chemical bond forming, they are referred to as mixtures
A solution forms when the components are evenly distributed
a solvent dissolves a solute
Salts and CO2 in the blood are examples
How easily the solute dissolves is called solubility
A suspension forms when the components separate into tiny pieces but do not dissolve
Red blood cells in plasma is an example

11. The universal solvent
The hydrogen bonds allow water to dissolve both polar covalent and ionic compounds.
This means it dissolves more things than any other solvent.
Our body uses it to:
Filter waste in the kidneys
Carry oxygen through the blood (returns some carbon dioxide)
Carry nutrients and vitamins through body

12. Water is almost clear
This allows light to pass through it to many organisms in shallow water (think pond, river stream, coastal areas of oceans).
And that allows for photosynthetic organisms to serve as the base of food chains in aquatic ecosystems

13. Water is less dense as a solid
Water is most dense just before it freezes.
But when it freezes it traps air between the crystals causing it to be less dense.
This allows ice to float
—which is nice for animals that would be crushed when a body of water freezes over