Compound

A compound is a substance made when two or more elements chemically combine, creating a new material with different properties from the individual elements. For example, water (H₂O) is a compound formed from hydrogen and oxygen atoms bonded together. The key is that the elements in a compound are bonded at the atomic level, resulting in a fixed ratio. Compounds can have unique characteristics and behaviors that differ significantly from their constituent elements, and they are created through chemical reactions, not just physical mixing.