What is a characteristic of a compound?

A compound is defined as a substance formed when two or more elements chemically bond together in a fixed ratio. One key characteristic of a compound is that it has properties that are different from the individual elements that make it up. This occurs because the chemical bonding alters the properties of the elements, leading to the formation of entirely new characteristics.

For instance, water (H2O) is a compound composed of hydrogen and oxygen. Neither hydrogen nor oxygen alone possess the properties of liquid water; however, when they bond in the prescribed ratio, the compound exhibits unique properties such as being a solvent and having a specific boiling point. This distinction emphasizes the fundamental nature of compounds and how their properties are a result of the interactions between the combined elements.

The other options describe aspects that do not accurately represent the definition of a compound. Compounds can consist of two or more different elements rather than just one type; they cannot typically be separated by physical means but rather require chemical reactions to break the bonds; and they are not composed of single atoms but rather of groups of atoms chemically bonded together. Thus, the correct understanding of a compound hinges on the unique properties that emerge from the combination of different elements.