Isomers that can be interconverted by rotation around a single bond are called....

Compare the stabilities of the following two compounds $(A)$ and $(B)$:
$A$ : $cis-1$-ethyl-$3$-methylcyclohexane
$B$ : $trans-1$-ethyl-$3$-methylcyclohexane

Different conformations of the same molecule are called

How can you define skew conformation?

The Newman projection representation of $CH_3-CH_2-CH(CH_3)-CH_2-CH_3$ about the $C_2-C_3$ bond is shown. Then $X$ and $Y$ are respectively:

The most stable conformation of $n-$butane is