what is the name of this hydrocarbon? 1 - methylbutane 2 - methylbutane 2 - methylpropane 3 - methylpropane

what is the name of this hydrocarbon? 1 - methylbutane 2 - methylbutane 2 - methylpropane 3 - methylpropane
Answer
Brief Explanations:
- First, count the longest - carbon chain. Here, the longest carbon - chain has 4 carbon atoms (butane).
- Then, identify the position of the methyl group. The methyl group ($-CH_3$) is attached to the second carbon atom of the butane chain. According to IUPAC naming rules for alkanes with substituents, we name it 2 - methylbutane.
Answer:
2 - methylbutane