Elements, Compounds, and Mixtures

Review key concepts and vocabulary related to elements, compounds, and mixtures.

Atom

The tiny particles that make up matter, measured in nanometers.

Element

The simplest substances that cannot be broken down any further.

Molecule

A group of two or more atoms held together by chemical bonds; the smallest unit of a chemical compound.

Chemical bond

A force of attraction between two atoms that allows them to form a chemical bond.

Compound

Molecules that are made up of two or more elements that are chemically combined.

Mixture

A physical combination of two or more substances that retain the properties of the individual substances.

Homogeneous mixture

A mixture that is not easily separated and hard to see the different parts.

Heterogeneous mixture

A mixture that is easily separated and where parts are visible.

Chemical formula

A code that tells what elements are connected to make a substance and how many atoms there are of each element.

Common name

The name by which a substance is identified in everyday life.

Chemical name

The way a chemist describes a substance, usually naming the elements that make it up.