Elements, Compounds & Molecules How can we classify matter?

Element A pure substance made up of one type of atom that cannot be broken down Each element can be identified by the type of atom it is made of Examples: Gold, Carbon, Iron

Molecule Two or more elements that have been chemically combined Molecules can be made by combining the same atom or different atoms Examples: Molecule made from more than one type of atom Molecule made from one type of atom

Compound Two or more different atoms that have been chemically combined When different atoms combine to form a compound, the properties are different than the properties of the atoms/elements that make it up. Example: Chlorine is a yellow, toxic gas. Sodium is a white, reactive metal. But sodium chloride is neither toxic nor reactive.