1. Week 14 Warm-ups

2. Agenda

3. Properties of Water • Water exists in 3 states naturally on earth: solid- ice,liquid- water,gas – vapor/steam (Water gains energy as it changes from a solid to liquid to gas – the molecules speed up and spread out) • The solid (ICE) floats in the liquid(molecules form a pattern with spaces in it so it is less dense) • Water holds a lot of heat • Water dissolves things(because it’s polar!) Nature has been cleaning water for billions of years. BUT, we are making water dirtier faster than nature can clean it! So what can we do???

4. The Water Molecule • Water is a molecule, made of two types of atoms: 2 hydrogen and 1 oxygen • H2O molecules form when H and O atoms share electrons • Water molecules are polar because they have electrically charged areas: H side is +O side is - • Opposites attract, likes repel. H2O molecules “stick” together: it’s called cohesionwhich causes surface tension & capillary action. polar Atoms are like letters, molecules are like words.

5. Peer Evaluation • Read the assigned Learning Log (or Picture) out loud, as a group. Choose one person to write the group’s comments • Write comments in a different color: • GOOD: what did they do well? • IMPROVE: what specifically do they need to do to make it full credit? • Do the same, but with a different writer each for the rest of the papers.