LIFE DEPENDS ON
THE UNIQUE
PROPERITIES OF
WATER
Physical Properties- can be
observed and measured


Water is a form of
matter
Matter- anything that
occupies space and
has mass
What happens when you put an
ice cube in a glass of water?

Why????

What do you think would happen to a can
of coke and diet coke if we placed it into a
container of water? Float? Sink? Why?
THE STRUCTURE OF WATER


Made up of two
covalently bonded
hydrogen atoms to an
oxygen atom
Polar Molecule- a
molecule that has
opposite ends with
opposite charges
THE STRUCTURE OF WATER

Hydrogen Bondweak attraction, bond
between a hydrogen
atom of a molecule
and a slightly
negative atom within
another molecule.
WATER’S LIFE SUPPORTING
PROPERTIES
Cohesion
 Adhesion
 Temperature Moderation
 Low Density of Ice
 Water’s Ability to Dissolve Other
Substances

COHESION AND ADHESION


Cohesion- the
tendency of
molecules of the
same kind to stick to
one another
Adhesion- an
attraction between
unlike molecules
COHESION AND ADHESION



Example: water transport
of trees/plants
Evaporation pulls water
which are attached by
cohesion up from the
roots.
Adhesion of water to the
walls of veins resist the
downward pull of gravity
Drops On a Penny

How many drops
fit on the penny?

Explain the bubble
that forms on
penny
COHESION AND ADHESION

Surface Tensioncohesion which pulls
the molecules at the
surface tightly
together
When have you experienced
surface tension?

http://www.youtube
.com/watch?v=6eh
93mut9K4&feature
=relmfu
Basilisk Lizard

http://www.youtube.com/watch?v
=45yabrnryXk&feature=fvw

http://www.teachertube.com/view
Video.php?video_id=96527
TEMPERATURE
MODERATION
Thermal Energy- total amount of energy
associated with the random movement of
atoms and molecules in a sample of
matter.
 Temperature- a measure of energy of
random motion of particles in a substance

TEMPERATURE
MODERATION

When two
substances differ in
temperature, thermal
energy in the form of
heat is transferred
from the warmer
substance to the
cooler one
TEMPERATURE
MODERATION




When you heat
molecules move faster
When you cool
molecules move slower
Water takes more energy
to heat because of
hydrogen bonds
Water retain heat longer
because of hydrogen
bonds
LOW DENSITY OF ICE


Density- amount of
matter in a given
volume
In most substances
the solid state is
more dense than the
liquid state
LOW DENSITY OF ICE



Water’s solid state is
LESS dense than the
liquid state
WHY?????
Hydrogen bonds in
ice (solid) keep
molecules spaced out
LOW DENSITY OF ICE



Since ice is less
dense than water it
floats
Ice prevents oceans
from freezing over
Ice insulates the
liquid water below
allowing life to persist
WATER’S ABILITY TO DISSOLVE
OTHER SUBSTANCES



Solution- a uniform
mixture of two or more
substances
Solvent- the substance
that dissolves the other
substance and is present
in greater amounts
(water)
Solute- the substance
that is dissolved, present
in a lesser amount (salt)
WATER’S ABILITY TO DISSOLVE
OTHER SUBSTANCES


Aqueous Solutionwhen water is the
solvent
Water molecules
surround ions and
break them apart
WATER’S ABILITY TO DISSOLVE OTHER
SUBSTANCES
Water is the
“Universal
Solvent”
 Water is the main
solvent inside all
cells, blood, and
plant sap

Wrap Up!

http://www.youtube.com/watch?v=QH1yphfgfFI

Structure of Water Molecule = Bent. Why?
5 Unique Properties of Water:





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1. Cohesion
2. Adhesion
3. Temperature Moderation
4. Low Density of Ice
5. Water’s Ability to Dissolve other Substances
Exit Slip
1. Explain how the structure of water
molecules results in attractions among
them.
 2. Give an example of how cohesion
among water molecules is important to
living things.
 3. Explain one way in which water can
moderate temperature.
