1. Physical and Chemical Changes

2. Physical Change
A change that affects one or more physical properties of a substance
Chemical identity remains unchanged
Appearance, shape, or size may be altered
Example: wool

3. Physical Change Change in state of matter is a physical change
Ex. Boiling, freezing, melting, subliming, deposition, condensation

4. Chemical Change
A chemical change occurs when one or more substances change into entirely new substances with different properties.
Example: cake

5. Chemical Change vs Properties
Burning is a change, flammability is a property
Chemical properties describe which chemical changes can or cannot occur
Chemical changes are the process by which substances actually change into new substances

6. Identity Change? Particles and chemical bonds get rearranged
Often times this rearrangement involves some sort of temperature change
Higher temperature means higher kinetic energy
This allows particles to move around faster and rearrange more easily
Back to the cake example

7. How Can You Tell? Production of a gas Production of an odor
Bubbling, fizzing, foaming
Production of an odor
Rotting eggs, sour milk, lightning changing the smell of the air
Formation of a Precipitate
A precipitate is a solid formed from a reaction of 2 liquids
Example: potassium iodide and lead nitrate react to form lead iodide
Change in color
Change in Energy
Often times seen as light or felt as heat

8. Change
Observation
Type of Change
Metal Rusting
Ice Cream Melting
Painting a Door
Baking cookies
Barbequing Chicken

9. Law of Conservation of Mass
The law of conservation of mass states that in ordinary chemical and physical changes, mass is not created or destroyed but is only transformed into other substances
Discovered by Antoine Lavoiser