20 butyl chloride and 30 butyl chloride are a pair of

20 butyl chloride and 30 butyl chloride are a pair of chain isomers.CH3-CHCl-CH2-CH3 .... 2-chlorobutane          and   CH33C-Cl ......... 2-chloro-2-methylpropane ; They differ in root word. They are chain isomers.