The Unique Properties of Water http://www.youngausskeptics.com/wp/wp-content/uploads/2009/06/watermemory2.jpg

Water is very common!  Water is the most common liquid on Earth. It covers three-fourths of Earth’s surface and makes up from 70 to 95 percent of the weight of living things.  http://www.oera.net/How2/PlanetTexs/EarthMap_2500x1250.jpg

Because water is polar… (-) (+)

It sticks to other molecules…

It sticks by forming weak hydrogen bonds

That’s called… Adhesion Cohesion When it sticks to another water molecule Adhesion When it sticks to another kind of polar molecule

Water is a good solvent! If you put sugar in your coffee or tea, you already know that water is an excellent solvent. The polar water molecules hydrogen bond to the salt, breaking it up until you can’t see them. http://www.elmhurst.edu/~chm/vchembook/images2/171saltdissolve2.gif

Water has high surface tension! Because water is polar, many water molecules hydrogen bonding causes the surface layer of water molecules to act like a stretched film over the surface of the water. This property of water is called surface tension. http://www.youtube.com/watch?v=45yabrnryXk&NR=1&feature=fvwp

Water expands when it freezes! Because water is polar, ice is less dense than liquid water and floats as it forms on a pond. Water expands when it freezes inside the cracks of rocks. As it expands, it often breaks apart the rocks. Over long periods of time, this process will form soil. http://www.ezstreetdiy.com/images/potholes/potholes-lg.jpg

Water can do capillary action! Because water is polar, water can pull up other water molecules (cohesion) and stick to the sides of plant tubes (adhesion). This property is called capillary action and plays a major role in getting water from soil to the tops of even the tallest trees.

Water resists temperature change! Water requires a lot of heat to increase its temperature. Likewise, water loses a lot of heat when it cools. This property of water is extremely important because temperature variations have a strong effect on the kinds of organisms that can live in a given region.    http://upload.wikimedia.org/wikipedia/commons/archive/c/c4/20080716214432!Virginia_Beach_from_Fishing_Pier.jpg

Water cools things when it evaporates! Because water is polar, it takes a lot of energy to make water evaporate. When water evaporates into the air, it carries away some heat and helps to cool the body. Hmmm…homeostasis! http://www.tapintoquality.com/facts/glossary/evaporation.jpg

Use the notes you just took to put at least one key word in each of the station boxes