* Components: Rainwater is primarily made up of water (H₂O), but it also contains dissolved gases (like oxygen and carbon dioxide), minerals, and sometimes pollutants. These components are not chemically bonded together.

* Variable Composition: The composition of rainwater can vary greatly depending on factors like location, air pollution levels, and the source of the water vapor.

* Separation: The components of rainwater can be separated by physical means. For example, evaporation leaves behind dissolved minerals, and distillation can separate water from dissolved gases.

In contrast, a compound is formed by the chemical combination of two or more elements in a fixed ratio. Water itself is a compound because it's formed by the chemical bonding of hydrogen and oxygen atoms. But rainwater is more than just water; it contains other substances that are not chemically bonded to the water molecules.