Pure Substances: Elements and Compounds. Mixtures: Homogenous and Heterogenous.

Heterogenous Mixture

A mixture where the substances that make up the mixture are mixed in differently throughout.

Element

A material made of only *one type of atom*. Found on the periodic table. Examples: He, Na, O₂, O₃, F₂, S₈

Homogenous Mixture

A mixture where the substances appear the same throughout.

Atom

The basic building block of all things. Different kinds of atoms are called elements.

Molecule

Two or more atoms bonded together. Can be elements like O₂ or compounds like H₂O.

Mixture

Two or more substances that are mixed but not chemically combined. More than one type of materials is present. Each substance in a mixture keeps its properties. Mixtures can usually be easily separated.

Pure substance

a material in which all of the particles are identical (the same). Only one type of element OR one type of compound is present. Examples: pure water, pure helium, pure copper, etc.

Compound

a material which is made of two or more different kind of atoms that are chemically combined (or bonded). Examples H₂O, CO₂, C₆H₁₂O₆