Warm Up: Write 10 facts you already know about water.

What is WATER? Water is a molecule It is also a compound. Why? What makes is a compound?

The word water usually refers to water in its liquid state. What is WATER?

Pure water has NO smell or taste, and a pH of 7 so it is not acidic or basic That makes it NEUTRAL

Structure of Water One water molecule is: Two hydrogen atoms (H 2 ) chemically bonded to one oxygen atom (O)

Structure of Water Hydrogen ends are slightly more positive. Oxygen end is slightly more negative. This means that water is a polar molecule WHY?????

Models of Water Molecules

Let’s let TED explain it!

Properties of Water Water has four properties that make it unique. 1. Cohesion 2. Adhesion 3. Capillary Action 4. Universal Solvent

Cohesion is when water molecules stick to other water molecules (attract each other like magnets) Cohesion at the surface of water is called surface tension.

SURFACE TENSION PICS

More SURFACE TENSION PICS Surface Tension – Cohesion at the surface creates a thin “skin” on the water.

More SURFACE TENSION PICS

Adhesion is when water molecules stick to other materials Dew –water drops on a spider’s web.

Capillary Action When a liquid moves up very narrow tubes because of cohesion and adhesion against gravity. Ex: plants bring water up through their roots to their stems and leaves

Capillary Action A meniscus is when the liquid “climbs” the sides of a graduated cylinder. glass surface

Universal Solvent Water’s polarity gives it the ability to dissolve many different substances. Almost every substance can dissolve in water over time.

Universal Solvent Almost…

3 States Water is the only substance on Earth that commonly exists in all 3 states. Liquid – Water Solid – Ice Gas – Water Vapor

Changing States Water can easily move between its three different states through several natural processes

WATER

Another way of looking at changes in state!

Websites from the Presentation Other cool water related videoshttp:// 1. (Surfing) 2. (Capillary action in trees) 3. (Super-cooled water) 4. (Walking on water – sort of!)