1. Properties of Water Essential Questions:
What are the properties of Water?
What are Mixtures, Solutions and Suspensions?
Why is water important for living things?

2. Introduction to Water
Consists of 1 Oxygen atom and 2 Hydrogen atoms per 1 water molecule.
How is water bonded?
Covalent Bonds
Carries substances via Osmosis.
Serves as material transportation
Blood, plant sap
Water makes up 70-95% of organisms.
Because of its bonding it can hold large molecules like proteins together.
Cycles through the kidneys and eliminated out of the body

3. Five Major Properties of Water
** Water has three phases: Solid (ice), liquid, gas (vapor)‏**
1. Water is liquid at room temperature, boiling point is high at 100° C; low molecular weight molecules are usually gaseous.
- Water resists temperature change (insulator)‏.
2. Water has a high freezing point and ice is less dense than water. (Thus, ice floats in water.)
3. Water is the universal solvent for polar and ionic molecules (means it dissolves things)
Hydrophilic: means “water-loving”, molecules that interact with water, soluble in water
Hydrophobic: means “water-fearing”, insoluble in water
Polar: Means it has a slightly positive (+) end and a slightly negative (-) end.

4. Five Major Properties of Water
4. Water is sticky:
Why? Hydrogen bonds keep water together (polar areas attract)
Slightly negative (-) Oxygen end
is attracted to the slightly
positive (+) Hydrogen ends.
Cohesion: attraction of water to other water molecules.
Adhesion: attraction of water to other types of molecules.
Capillary Action: Can adhere creep up tubes. Ability of a substance to draw another substance into it.
Examples:
- The meniscus in a graduated cylinder.
- Water up a tree.

5. Five Major Properties of Water
5. Water has high surface tension
water is more attracted to itself than to the air around it
Sticks together (+ and – attract.)

6. Five Major Properties of WaterL U S H
REEZING POINT IS HIGH
Great
insulator!
IQUID AT ROOM TEMPERATURE
NIVERSAL SOLVENT
URFACE TENSION IS HIGH
YDROGEN BONDS

7. Mixtures, Solutions & Suspensions
A mixture is a combination of substances where both substances keep their original properties.
Physically mixed, not chemically mixed.
They can be easily separated.
Solution – one or more substances (solutes) are distributed evenly in another substance (solvent) (water)‏
The more solute in a solvent, the higher the concentration.
Organisms need to maintain a certain concentration for life processes, called homeostasis.
Suspensions – mixtures of water and non dissolved particles
Example: Blood
Like sugar and salt.
Like lemonade.
Like blood! Many
cells are suspended
in blood

8. Mixtures, Solutions & Suspensions
A mixture is a combination of substances where both substances keep their original properties.
Physically mixed, not chemically mixed.
They can be easily separated.
Solution – one or more substances (solutes) are distributed evenly in another substance (solvent) (water)‏
The more solute in a solvent, the higher the concentration.
Organisms need to maintain a certain concentration for life processes, called homeostasis.
Suspensions – mixtures of water and non dissolved particles
Example: Blood
Water and salt–
Solution
Sand and water –
Suspension
Sand and shells –
Mixture

9. Homeostasis
The ability or tendency of an organism to maintain internal equilibrium, or balance, internally.
Think back to the kidneys…
If we are dehydrated, our kidneys
keep water!
If we are hydrated, our kidneys
lose the excess water!