Which statement is true about a homologous series?

A homologous series is defined as a group of organic compounds that share a common structural feature and display similar chemical properties as well as a gradual change in physical properties. The members of a homologous series share the same functional group, which means they all have similar chemical reactivity. Additionally, they follow a specific general formula that describes their structure.

For example, in the case of alkanes, the general formula is CnH2n+2, where "n" is the number of carbon atoms. Each member of the series differs from the next by a specific unit, typically a -CH2- group, not -CH3, which reinforces their classification as a homologous series.

The uniqueness of boiling points among members of a series can vary due to factors like branching or intermolecular forces, but it is not a defining characteristic of a homologous series. Thus, the statement that all members share the same general formula and functional group is accurate and represents the essence of a homologous series.