# What method is used to distinguish between different molecular compounds that contain the same elements?

Let's assume you have the chemical formula ${C}_{5} {H}_{12}$.....Three structural isomers can be generated by this formula: (i) "n-pentane", H_3C-CH_2CH_2CH_2CH_3; (ii) "isobutane", H_3C-CH(CH_3)CH_3; and (iii) $\text{neopentane} , C {\left(C {H}_{3}\right)}_{4}$.
And we have to choose a spectroscopic means to differentiate these isomers. In this scenario the best means is ""^1H $\text{NMR spectroscopy}$, which for isomers, (i), (ii), and (iii), would generate 3 signals, 2 signals, and 1 signal respectively......the first two with the appropriate integral ratio, i.e. $6 : 4 : 2$, and $9 : 1$.