Answer :
1. All matter is composed of extremely small particles called atoms, which cannot be subdivided, created, or destroyed.
2. Atoms of a given element are identical in their physical and chemical properties.
3. Atoms of different elements differ in their physical and chemical properties.
4. Atoms of different elements combine in simple. whole-number ratios to form compounds
5. In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed.