of the hydrogens given here, which is the heaviest?
butane
nonane
octane
propane
butane-Mw-58.12 g/mol............3
nonane-Mw-128.2 g/mol...........1
octane-Mw-114.23 g/mol...........2
propane-Mw-44.1 g/mol.............4
Given the above, it is obvious. Mw=Molecular weight.