1.4 Composition of Mixtures

Explain the quantitative relationship between the elemental composition by mass and the composition of substances in a mixture.

• Pure substances contain atoms, molecules, or formula units of a single type. Mixtures contain atoms, molecules, or formula units of two or more types, whose relative proportions can vary.
• Elemental analysis can be used to determine the relative numbers of atoms in a substance and to determine its purity.