1. All matter is composed of extremely small particles called atoms.
2. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties (not true).
3. Atoms cannot be subdivided, created, or destroyed (not true).
4. Atoms of different elements combine in simple whole number ratios to form chemical compounds.
5. In chemical reactions, atoms are combined, separated, and rearranged.