1. The Grand Gel Challenge!

2. The Grand Gel Challenge Physical and Chemical Changes of Properties

3. Change all around us Things around us are always changing Since everything in the world is made up of matter, they constantly undergo change These changes can be classified as either physical or chemical

4. Physical Change Substance changes its physical appearance but it’s reversible No change in identity and composition of substance, no new substance produced Example: change from ice cube to liquid

5. Signs of physical change: Size Shape Density Solubility Melting point or boiling point Changes of state (solid, liquid, gas)

6. Chemical Change The way a substance may change or react to form other substances Substance transformed into a chemically different substance Example:

7. Signs of chemical change: Change in color or odor Absorption or release of energy (light, heat, sound) Formation of a precipitate Generation of a gas (bubbles)

8. Examples: is it physical or chemical? Blowing up a balloon Your stomach digesting food Liquid water boiling and turning to steam Burning a piece of paper Salt dissolved in water Breaking a bottle Plant going through photosynthesis Baking a cake