Properties of Water An interesting molecule! Water.in chemical language Water is written as H 2 O That means that it is made of 2 hydrogen molecules and 1 oxygen molecule Structure of Water Water is made up of one oxygen atom and 2 hydrogen atoms They are linked by a covalent bond Did the Jello mix better in the oil or the water?? The WATER!!! The worlds greatest solvent! Water mixes really well with most things! This is because water can stick to things! The oxygen has 8 protons and the hydrogen only have 1 proton each Since the shared electron has a negative chargedo you think that electron likes to spend more time by the hydrogen atoms or the oxygen? Brain Workout A Polar Molecule Molecules with an uneven distribution of charge are called polar molecules Polarity A pole just means one side ofso to be polar means that one pole is positive and one pole is negative. CFU What 2 elements is water made of? 2 hydrogen molecules and 1 oxygen molecule CFU What does it mean to be a polar molecule? That there is an un-even distribution of charge CFU Which is more negative?? A. Oxygen B. Hydrogen C. Neither, they have the same charge Lets Build Water Molecules! Please use your cut-outs to build a water molecule We can hang these up in our classroom to help remind us what a polar molecule is! Mix it Up! We dont usually find water in its pure form, generally something is mixed into it! Mix it up some more There are 2 types of water mixtures Solutions Suspensions Solutions All the components of the mixture are evenly distributed in the water Example: salt in hot water Solution Solutions Solute = what you mix in Solvent = what you mix it into Solute Solvent Solutions Example salt into water Solvent Solute Salt! Water Question If I am making chocolate milk which is the solute and which is the solvent? Suspensions When you mix something into water and it does not mix all the way in. CFU What is a solution? A mixture where everything is evenly distributed in the water CFU Derrick is making some black cherry kool-aid. Is the kool-aid mix the solute or the solvent? A. Solute B. Solvent CFU Is oil and water an example of a solution or a suspension? A. Solution B. suspension Cohesion Because the water has both negative (-) and positive (+) charges on it, water molecules attract each other! This is called COHESION Cohesion Look at your paper water molecules How would your water molecule stick with your neighbors? Cohesion is Cool! Cohesion allows for something called surface tension This is why bugs can walk on water and you can fill a water glass to the brim! When water molecules are attracted to things other than water, it is called adhesion. Adhesion Make a connection! Cohesion is when water is attracted to itself and adhesion is when it is attracted to something other than water! CFU In this picturewhere do you see adhesion? CFU In this picturewhere do you see cohesion? Why does ice float? Water Density Water is less dense in its frozen form..but what does that mean? It means that the water molecules are more spread out in ice than they are in liquid water. Lets take a closer look at density Density Density is a measure of how close molecules are to each other Liquid water has a HIGH density Solid water has a LOW density Frozen vs. liquid Liquid WaterIce High Density, the molecules are close together Low Density, the molecules are far apart Acids, Bases and the pH scale