1. Chemical Properties
Property of matter that describes a substances ability to participate in chemical reactions. (Change into new matter.)
Flammability
ability to burn
Burning wood creates ash and smoke
Reactivity
ability of two or more substances to combine and form a new substance
Oxygen and iron create rust

2. Physical and Chemical Properties
Comparing
Physical and Chemical Properties
Physical properties may be observed without changing the identity of the substance.
Density, Hardness, Color
Chemical properties can not be observed until the chemical reaction takes place.
A piece of wood is flammable even when it is not burning, but must be burning to observe this property

3. Characteristic Properties
Properties most useful in identifying a substance.
Always the same no matter the size of the sample
Physical properties
Density, Hardness
Chemical Properties
Flammability, reactivity
Used to identify and classify substances

4. Chemical Change
When two or more substances are changed into an new substance
Learn about chemical properties through chemical changes
Examples:
Digestions
Burning wood
Rust
Soured milk

5. Signs of a Chemical Change
What Happens During
A Chemical Change
Ingredients combine to form a new substance
Baking a cake
Change in color, odor
Production of heat, sound, light
Change the identity of the matter involved
This makes them very hard to reverse
Some chemical changes can be reversed
Water split back into oxygen and hydrogen using electric current
Signs of a Chemical Change
Matter & Chemical Changes

6. Physical vs. Chemical Change
Did the composition change?
Composition is the type of matter that makes up an object and the way that matter is arranged
Chemical changes alter the composition of the substance.
Many physical changes may be easily reversed
Melted ice cube can be frozen again
Chemical Changes are not easily reversed
Water separated into hydrogen and oxygen
Reversing Changes