When two or more elements are chemically combined, they form a compound. A compound is a pure substance that consists of atoms of different elements bonded together in a fixed proportion. The properties of a compound are different from the properties of the elements that make it up. Compounds can only be separated into their constituent elements by chemical means, not physical methods. In summary:
- Two or more elements combined chemically form a compound.
- Compounds have fixed ratios of atoms.
- The compound's properties differ from those of its constituent elements.
- Compounds are distinct from mixtures, where elements or compounds are physically combined but not chemically bonded.
Examples include water (H₂O), which combines hydrogen and oxygen, and table salt (NaCl), combining sodium and chlorine.
