Water is essential for living things because it makes up most of their bodies. It has unique properties including polarity, hydrogen bonding, and temperature moderation. Polarity gives water polar molecules that allow it to dissolve many substances. Hydrogen bonding between water molecules accounts for its three states as a solid, liquid, or gas and allows water to stick to itself and other surfaces. Its high heat capacity means water absorbs large amounts of energy during temperature changes to maintain homeostasis in organisms.

1. Properties of Water NotesProperties of Water Notes

2. WaterWater
• Why is water important to living things?Why is water important to living things?
• All living things are mostly made out ofAll living things are mostly made out of
water.water.

3. Water StructureWater Structure
• Water consists of 2Water consists of 2
hydrogen and 1hydrogen and 1
oxygen atom.oxygen atom.
• They are heldThey are held
together by a covalenttogether by a covalent
bondbond
• Covalent Bonds-Covalent Bonds-
means they sharemeans they share
electrons.electrons.

4. WaterWater
• Three properties of water make it a uniqueThree properties of water make it a unique
substance:substance:
• 1. Polarity1. Polarity
• 2. Hydrogen Bonding2. Hydrogen Bonding
• 3. Temperature Moderation3. Temperature Moderation

5. PolarityPolarity
• 1. Polarity1. Polarity - uneven pattern of charge- uneven pattern of charge
due to an unequal sharing of electrons indue to an unequal sharing of electrons in
the covalent bond.the covalent bond.
• The Oxygen pulls the electrons towards itThe Oxygen pulls the electrons towards it
cause it to be negative charge and thencause it to be negative charge and then
making the top part with the Hydrogens tomaking the top part with the Hydrogens to
be positive charge.be positive charge.

6. PolarityPolarity
• Benefits of polarity:Benefits of polarity: Water is able toWater is able to
dissolve other polar substances (likesdissolve other polar substances (likes
dissolve likes).dissolve likes).
• This makes water the universal solventThis makes water the universal solvent

7. Hydrogen BondingHydrogen Bonding
• 2. Hydrogen Bonding2. Hydrogen Bonding
- the positive region- the positive region
(hydrogen) of one(hydrogen) of one
water molecule iswater molecule is
attracted to theattracted to the
negative regionnegative region
(Oxygen) of another(Oxygen) of another
water molecule.water molecule.

8. Hydrogen BondingHydrogen Bonding

9. Hydrogen BondingHydrogen Bonding
• Hydrogen Bonding is what causes the 3Hydrogen Bonding is what causes the 3
state of matter.state of matter.
• SolidSolid – particles are barely moving, lots of– particles are barely moving, lots of
hydrogen bonds. Ex. Icehydrogen bonds. Ex. Ice
• Heat energy breaks the bonds that allow aHeat energy breaks the bonds that allow a
solid to turn into a liquid.solid to turn into a liquid.

10. Hydrogen BondingHydrogen Bonding
• LiquidLiquid - particles are moving slowly, few- particles are moving slowly, few
hydrogen bonds. Ex. Waterhydrogen bonds. Ex. Water
• GasGas - particles are moving very fast, no- particles are moving very fast, no
hydrogen bonds. Ex. Water vaporhydrogen bonds. Ex. Water vapor

11. Hydrogen BondingHydrogen Bonding
• Why: Polarity leads to uneven chargesWhy: Polarity leads to uneven charges
• Benefits:Benefits: Water can cling to itself andWater can cling to itself and
other substances. Examples of this areother substances. Examples of this are
Cohesion and Adhesion.Cohesion and Adhesion.

12. Water ClingsWater Clings
• CohesionCohesion: attractive force between: attractive force between
particles of the same kind, like waterparticles of the same kind, like water
sticking to water.sticking to water.
– ExEx.. Surface tensionSurface tension: waters acts as if it has a: waters acts as if it has a
thin skin, allows animals to walk on top of thethin skin, allows animals to walk on top of the
water, without falling in.water, without falling in.

14. Water ClingsWater Clings
• AdhesionAdhesion: attractive force between: attractive force between
particles that are different, like water toparticles that are different, like water to
glass or your blood to veins.glass or your blood to veins.
• Example would be capillarity and is howExample would be capillarity and is how
blood moves through your small veins.blood moves through your small veins.

15. Water ClingsWater Clings
– CapillarityCapillarity – water/liquid molecules move– water/liquid molecules move
upward through narrow tubes against theupward through narrow tubes against the
force of gravity – important for plants!force of gravity – important for plants!

16. Temperature ModerationTemperature Moderation
• Temperature ModerationTemperature Moderation - water must gain or lose- water must gain or lose
a lot of energy for the temperature to change.a lot of energy for the temperature to change.

17. Temperature ModerationTemperature Moderation
• Why:Why: Hydrogen bonds must break before there isHydrogen bonds must break before there is
a change in temperature and you need toa change in temperature and you need to
gain/loose heat energy to break bonds.gain/loose heat energy to break bonds.
• Benefits:Benefits: Homeostasis for marine life and withinHomeostasis for marine life and within
our cells.our cells.
• This is how our bodies can stay at 98.6 degreesThis is how our bodies can stay at 98.6 degrees
all day every day.all day every day.