- 3 principal states of matter: solids, liquids, and gases.
- Boiling point: is the temperature at which a substance changes from a liquid to a gas.
- Characteristic properties: for a give substance never changes, they can be used to identify unknown matter.
- Chemical activity: is a characteristic property of a substance that indicates its ability to undergo a specific chemical change.
- Chemical changes: are when substances combine or break apart to form new substances.
- Compound: is a substance made of two or more elements that are chemically combined.
- Elements: are substances that cannot be broken down in to other substances by any physical or chemical means.
- Matter: can be classified into two general categories: mixture and pure substances.
- Matter: is anything that has mass and takes up space.
- Melting point: is the temperature at which a solid changes from a solid to a liquid.
- Physical changes: alter the form of a substance, but not its identity.
- Pure substances: is made of only one kind of matter and has definite properties.