Think About Water
1.
2.
3.
How many water molecules
are present? (18)
How many Hydrogen bonds
have formed between water
molecules? (15)
Why can hydrogen bonds
form between individual
water molecules? (Because
water molecules are polar;
they have a poistive and
negative side to the
molecule. The negative
oxygen atom is attracted to
the positive hydrogen atom.)
Practice:
Draw (4) water molecules?
A) Label all the hydrogen and oxygen atoms on each molecule.
B) How many covalent bonds are found on one water
molecule?
How many drops of
water can you place on
the surface of a penny?
Check out
the drop of
water
The following slide review the
structure of water. The structure is
what helps organisms to survive
one earth.
Because water is polar, it can form hydrogen bonds. The formation of the hydrogen
bond makes water cohesive and adhesive. Click on next slide to understand the
difference between cohesive and adhesive.
We can use the properties of
water to explain why the large
number of drops can be placed
on the surface of the penny.
Click on the next slide to learn
about cohesion and adhesion
The drops of water on the leaves are like
the drops on the penny
• Cohesion causes water to form drops. It is the attraction of
water molecules to water molecules
• Surface tension causes the drops to be spherical because
they pull into each other
• Adhesion keeps the drops in place because it is the
attraction of water molecules to different water molecules
9
Surface of Penny
What happens to this setup?
Watch the video clip.
If the hydrogen bonds are disrupted, the molecules move apart. Surface
tension is weakened and the water runs off penny. Or, if the mass of water
become great, water will run off the penny.
What Happens to Water on Two Different
Surfaces?
Will Water Move Through Celery?
In pairs, create a model that will show if water can move
through celery…
1. Fill a beaker with water. Add a drop of food color. Mix the
water to evenly.
2. Obtain a piece of celery. Carefully slice one end with a
scalpel.
3. Place the cut end into the beaker of colored water.
4. Label the beaker with your name using tape and marker.
Write (5) observations on how the celery appears in your
notebook. You many take it out of the beaker to look at the cut
ends. Predict what
Here is what celery plant looks like? Look for
the roots, stem and leaves.
About Celery
• It’s a plant
• It’s stalk is the stem of
the plant.
• The stalk contains xylem
vessels which transport
water
• Vessels are organs which
are made of cells.
What will the celery look like after 24 hours in food color water?
24 Hours Later…………
Use cohesion, adhesion,
hydrogen bonds, and
capillary action and
transpiration to explain the
results of the “Water
Movement in Celery”
investigation.
Water: Life’s Supporting
Compound
Chapter 2 presents basic information on the science of
elements, compounds and chemical reactions. Our study
focuses on how water’s unique chemical structure to explain
how water moves from roots to leaves in plants.
Water is needed by all living things. Plants obtain water from
the soil (precipitation, percolation) and lose water through their
leaves (transpiration).
Now we see how transpiration not only moves water in the
water cycle but helps a plant to survive. Go to the next slide
and click on the link to watch the transport of water in plants.
If you are interested in other life supporting properties, feel free
to view the other links.
Video links about Water’s Life Supporting
Properties:
•
•
•
•
•
•
Salt Dissolving in Water
All About Water
Why does ice float?
Transpiration (How Water is Transported in Plants
Everyday Examples of the Properties of Water
water strider walking on water
Additional Information….
Watch the video on the Properties of Water.
Listen for the properties in the “Why is Water
Important in Biology video that would be used to
explain the Penny and Water activity
The second link is a summary of Water’s Unique
Properties.
Why is Water Important in Biology
Properties of Water