 Watershed=an area of land where all of the water drains into the same place (a particular stream, lake, river, or wetland).  Watersheds come in all shapes and sizes. “Watersheds can be as small as a footprint or large enough to encompass all the land that drains water into rivers that drain into Chesapeake Bay”

 In the continental US, there are 2,110 watersheds.

1. Lower Mississippi River 2. Upper Mississippi River 3. Missouri River 4. Ohio River 5. Arkansas River 6. Columbia River 7. Rio Grande River

 Current USGS Water Data for the Nation Current USGS Water Data for the Nation  U.S. Drought Monitor U.S. Drought Monitor

 Surf Your Watershed Surf Your Watershed

 Video Introduction Video Introduction Cohesion: attraction between molecules of the same substance -In water, cohesion causes surface tension. Adhesion : attraction between molecules of different substances Surface tension: water molecules at surface form stronger bonds

Walking on water: Small insects such as the water strider can walk on water because their weight is not enough to penetrate the surface. Floating a needle: A carefully placed small needle can be made to float on the surface of water even though it is several times as dense as water. If the surface is agitated to break up the surface tension, then needle will quickly sink. Surface Tension and Droplets: Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer.

 How many drops of water can you fit onto a penny before it overflows?  Do three trials, drying the penny in between each.  Now, have Ms. Spoon add a little soap to the surface of your penny and then see how many drops you can get to fit on the penny. What do you predict will happen?  Penny Lab! Penny Lab!

 What property of water allows drops to collect on the surface of the penny?  What type of attraction do the water molecules have with each other?  What type of attraction do the water molecules have with the penny?