1. Water Chemistry Mrs. Wisher

2. What is Chemistry?  Chemistry is the study of the properties of matter and how matter changes  Matter – the stuff that makes up everything in the universe

3. Chemistry of Water  Elements are made up of atoms  Compounds & mixtures are made up of elements combined together  Examples  NH 4  CO 2  H 2 O!

4. Chemistry of Water  Water or H 2 O is a compound  A chemical compound of 2 hydrogen atoms & one oxygen atom  The most abundant chemical compound on Earth  Covers 70% of the Earth’s surface  A water molecule can spend 3,200 years in the ocean before going through the water cycle and up to 10,000 years in deep- underground caves.

5. Physical Changes  Water changing it’s state is a physical change  This is a vital part of the water cycle  What are the different ways that the water cycle changes it’s state?  Evaporation  Condensation  Precipitation  Sublimation

6. Water as a Solid  Water exists as ice below 0 0 C  This is the freezing point  The molecules of H 2 0 are in a fixed position yet vibrate  As the molecules are heated they vibrate more rapidly

7. Water as a Liquid  As the temperature of the water molecules heat up, they begin to vibrate quickly  In a liquid phase, the molecules have a little room to slip past each other but are still fixed

8. Water as a Gas  When the temperature of water rises to 100 0 C, the molecules move around more freely  We call this the boiling point  The water molecules escape the liquid state and turn into a gas