Which of the following statements is not true about a homologous sereies?

Homologous series:→ A series of compounds which have same general molecular formula, showing same chemical properties and regular gradation in physical properties is said to be homologous series.→ Each member in a homologous series is said to be homologue.Eg: alkanes -G.M.F: CnH2n+2 [n = no of carbons]→ All the memebers of homologous series can be prepared by the same general methods.Eg.