• Polar Molecule: _____________________________________
___________________________________________________
– The are more electrons surrounding the oxygen atom than the hydrogen atoms.
– Oxygen atom has a slightly negative charge.
– Hydrogen atoms has a slightly positive charge.
• Hydrogen Bonds: ____________________________________
___________________________________________________
___________________________________________________
• How is a hydrogen bond different than a covalent bond?
___________________________________________________
___________________________________________________
___________________________________________________
• Adhesion: __________________________
____________________________________
____________________________________
– Cohesion makes water have high
surface tension – it is difficult to break the surface of a body of water.
– Cohesion makes water a viscous
liquid – it is difficult to move through.
• Cohesion: ___________________________
____________________________________
____________________________________

• Capillary Action: ____________________________________
___________________________________________________
___________________________________________________
___________________________________________________
Examples of Capillary Action:
– Water flowing into the spores of a sponge
– Water flowing into plant roots and up the plant stem.
– Groundwater moving up through soil.

Water can mix other polar/ionic molecules.
– Polar molecules can be referred to as hydrophilic (water
loving)
– Solute : ______________________________________
_____________________________________________
– Solvent: ______________________________________
_____________________________________________

Ex: Salt (solute) dissolves in water (solvent).
– ____________________________________________________________________
– ____________________________________________________________________
– ____________________________________________________________________

Water does not mix with nonpolar molecules.
– Non polar molecules can be referred to as hydrophobic (water fearing).
– Water (polar) and oil (nonpolar) do not mix.

Water molecules are in constant motion. The higher the temperature the faster the molecules are moving.
The Three States of Water:
• Gas (vapor): _____________________________________________________________
________________________________________________________________________
– Water molecules are spread much further apart than in liquid water.
– Increasing temperature, increases the rate of evaporation.
• Liquid: _______________________________
______________________________________
______________________________________
– Hydrogen bonds are constantly being broken and reformed.
– Cold Water: ______________________
_________________________________
_________________________________
– Warm Water: ____________________
________________________________
________________________________
• Ice: ____________________________________________________________________
________________________________________________________________________
– In ice, the water molecules are further apart than in liquid water.
– Ice is less dense than liquid water.
– Why is it important that ice floats in the ocean?
___________________________________________________________________
___________________________________________________________________

Heat Capacity: ________________________________________________________________
• Water has the highest heat capacity of any natural substance.
• Heat energy must be used to break hydrogen bonds between water molecules before the molecules are able to move faster and increase temperature.
• A relatively constant water temperature helps organisms maintain
:
________________________________________________________________________
• It takes a long time and a lot of energy for water to heat up or cool down.
• Water’s high heat capacity protects organisms from drastic changes in temperature.
• Water molecules sometimes split apart to from ions.
• What is an ion?
__________________________
__________________________
__________________________
• Pure water is neutral:
__________________________
__________________________

pH: (power of Hydrogen) as in Hydrogen ions
• Measures the H+ concentration in solution: [H+]
• It is a log scale, so it increases by powers of ten.
• Ex: pH 2 = [H+] of 0.01M, pH 3 = [H+] of 0.001M
• Ex: A solution with a pH of 2 is ten times more acidic then a solution with a pH of 3.
1.
According to the scale, what substance is neutral?
2.
What solution has an [H+] of 0.0001M?
3.
Which substance produce the most OH- ions in solution?
4.
How many more times acidic is tomato juice compared to pure water.

Buffer: ________________________________
_______________________________________
_______________________________________
• Many land animals have buffers in their blood that maintain a constant pH.
• Ocean water acts as a buffer and resists changes in pH.
• If the pH of an organism changes, it will affect the chemical reactions inside their cells.
• Buffers help organisms maintain homeostasis with respect to pH.