Question

write the structures and name of two isomers of butane​

Answer 1

According to IUPAC nomenclature, these isomers are called simplybutane and 2-methylpropane. Notice that isobutane has a propane parent chain with a methyl group - CH3 attached to the second carbon of the chain - that is why its IUPAC name is 2-methylpropane

Answer 2

n butane and iso butane CH3-CH2-CH2-CH3 , CH3-CH2-CH3

CH3