Chem

Matter

A substance that has volume (occupies space) and has a mass.

Atom

The building block of matter.

John Dalton's Atomic Theory

Proposed in 1802 that all matter is made up of tiny spherical particles that are indivisible and indestructible.

Pure Substance

A substance made up of only one type of particle throughout, having a fixed composition and consistent properties.

Mixture

Consists of two or more different types of particles that are not chemically combined.

Element

A type of atom that shares the same number of protons, e.g., hydrogen has one proton, oxygen has eight protons.

Compound

A substance made up of two or more different elements that are chemically bonded together.

Monatomic

Elements that exist in individual atom form.

Polyatomic

Elements that prefer to form into molecules.

Molecules

Two or more atoms that are held together by chemical bonds.

Separation of Mixtures

Mixtures can be separated by physical processes such as filtration.

Separation of Pure Substances

Elements cannot be separated into simpler substances by physical or chemical means.