Classifying Matter: Atoms, Elements, & Molecules

Elements Atoms Molecules Pure Substances pure substance - A sample of matter that has definite chemical and physical properties. Made up of 1 type of particle Elements Atoms Molecules

Atoms atom – a small particle that makes up matter smallest particle an element can be divided and still be considered the same substance

Hydrogen Atom Oxygen Atom

Elements element - pure substance that cannot be separated into simpler substance by physical or chemical means made up of 1 type of atom each element can be identified by it’s properties properties do not change regardless of the sample size examples: boiling point, melting point and density (physical properties) and reactivity with an acid (chemical property).

Hydrogen Element Hydrogen Atom Oxygen Atom Oxygen Element

Molecules molecule - a group of atoms that are held together by chemical forces consist of a single element or different elements smallest unit of matter that can exist by itself and retain all of a substance's chemical properties

Hydrogen Element Hydrogen Atom Water Molecule Oxygen Atom Oxygen Element