Are the following molecules constitutional isomers?

Which of the following pairs of compounds are constitutional isomers?

Which pair of the following compounds are constitutional isomers?

Given the following pair of structures, indicate the relationship between them: Structure 1: $C_4{H}_{10}$ (n-butane) and Structure 2: $C_4{H}_{10}$ (isobutane).

How many constitutional isomers are possible for the molecular formula $C_6{H}_{14}$?

Give the relationship between the following pairs of structures. The possible relationships are:

same compound

constitutional isomers (structural isomers)

cis-trans isomers

not isomers (different molecular formula)

(g) CH₃–CH₂–CH₂–CH₃ and CH₃–CH=CH–CH₃

(h) CH₂=CH–CH₂CH₂CH₃ and CH₃–CH=CH–CH₂CH₃

(i) CH₂=CHCH₂CH₂CH₃ and CH₃CH₂CH₂CH=CH₂