In the Newman projection for 2,2-dimethylbutane X and Y can respectively be

Step-by-step solution

Conformation projection along C ₁- C ₂ C ₁ contains all three Hs So, X= H C ₂ contains two methyl and one ethyl group So, Y= C ₂ H ₅ Conformational projection along C ₂- C ₃ C ₂ contains three methyl groups ( C ₂ . form back carbon in the given structure) So, Y= CH ₃ C ₃ contains two Hs and one methyl group ( C ₃ . form front carbon in the given structure) So, X= CH ₃ C ₃ contains two Hs and one methyl group ( C ₃ . form front carbon in the given structure) So, X= CH ₃ Isomerism (Stereochemistry) Conceptual (Struct