What is a compound?

A compound is defined as a pure substance that consists of two or more different elements chemically combined in fixed proportions. This means that the elements within a compound are bonded together through chemical interactions, resulting in a substance with distinct chemical properties that are different from those of the individual elements.

For example, water (H₂O) is a compound formed from the chemical combination of hydrogen and oxygen in a 2:1 ratio. The characteristics of water cannot be deduced just by looking at hydrogen or oxygen alone, highlighting how compounds achieve unique properties through the combination of different elements.

In contrast, a mixture of substances does not involve any chemical bonding, meaning the properties of the individual components are retained. Similarly, a single element in its natural state does not fit the definition of a compound, as it does not involve multiple elements. Lastly, homogeneous mixtures consist of different substances that are uniformly distributed but are not chemically bonded, thus they also fail to meet the criteria that define a compound.