Which of the following compounds is NOT an isomer? [closed]








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Which of the following compunds is not an isomer? I cant figure out how the answer is d




The simple way would be to count to the number of each type of atom in each molecule. Alternatively, you could also note that only d has 1 [degree of unsaturation](https://en.m.wikipedia.org/wiki/Degree_of_unsaturation), while all the rest have 2.


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In this case, the simplest way is to find the molecular formula of each structure. Then, you'd see why (d) is the correct answer (isomers must have same molecular formula).


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