Think About Water 1.How many water molecules are present? (18) 2.How many Hydrogen bonds have formed between water molecules? (15) 3.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 Transpiration 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. Properties of Water Why is Water Important in Biology