In the Newman projection for 2,2-dimethylbutane

\(X\) and \(Y\) can respectively be

Conformation projection along \(\mathrm{C}_1-\mathrm{C}_2\)
\(\mathrm{C}_1\) contains all three \(\mathrm{Hs}\)
So, \(\quad X=\mathrm{H}\)

\(\mathrm{C}_2\) contains two methyl and one ethyl group
So, \(\quad Y=\mathrm{C}_2 \mathrm{H}_5\)
Conformational projection along
\(
\mathrm{C}_2-\mathrm{C}_3
\)
\(\mathrm{C}_2\) contains three methyl groups
\(\left(\mathrm{C}_2\right.\) form back carbon in the given structure)
So, \(\quad Y=\mathrm{CH}_3\)

\(\mathrm{C}_3\) contains two Hs and one methyl group
\(\left(\mathrm{C}_3\right.\) form front carbon in the given structure)
So, \(\quad X=\mathrm{CH}_3\)
\(\mathrm{C}_3\) contains two Hs and one methyl group
\(\left(\mathrm{C}_3\right.\) form front carbon in the given structure)
So, \(\quad X=\mathrm{CH}_3\)
Isomerism (Stereochemistry)
Conceptual (Structural visualisation) III