Do Organic compounds belonging to the same homologous series exhibit similar chemical properties and regular gradation in physical properties and the successive members differ by methylene group. 

Given data:It is given to identify homologous series have similar chemical & physical properties.

Explanation:

Homologous series is a class of organic compounds having same general formula & similar chemical and physical properties they differ by only −${\mathrm{CH}}_2$ groups .
Characteristics of homologous series :
(i) Each member of the series differs from one methylene group (−${\mathrm{CH}}_2$) and it is of 14 amu .
(ii) All members of a homologous series have the same elements and functional group .
(iii) A general molecular formula. Eg : Alkanes ,  ${\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}+2}$.
(iv ) They show a regular gradation in their physical properties with increase in molecular mass .
(v) Chemical properties of the members of a homologous series are similar.

Hence, homologous series have similar chemical & physical properties.