H H H H
! ! ! !
H-C-C-C-C-H :Butane
! ! ! !
H H H H
butane is an alkane
an organic isomer is a chemical with the same molecular formula as another but different molecular structure
H
H H-C-H H
! ! !
H - C - C - C - H : 2-methyl propane
! ! !
H H H
Hope that helps