Final answer:
The staggered Newman projection of 2-methylpentane is lowest in energy compared to the eclipsed conformation, as it minimizes torsional strain by spacing apart substituents on adjacent carbons.
Step-by-step explanation:
The Newman projections for 2-methylpentane about the C2-C3 bond show different spatial arrangements of atoms due to rotation around the bond. The staggered conformation is one where the atoms or groups on adjacent carbons are positioned with the maximum angle between them, which minimizes repulsions and thus is lower in energy and more stable. In contrast, the eclipsed conformation is one where the atoms or groups on adjacent carbons are aligned with each other, leading to increased repulsion and higher energy.
Conformations can be visualized and analyzed using Newman projection diagrams. The staggered conformation of 2-methylpentane would have the methyl group and other substituents on C2 and C3 arranged so that they are staggered relative to each other for minimum strain. As compared to the eclipsed conformation where substituents are directly behind each other, the staggered conformation is always the lowest in energy due to reduced torsional strain from electron repulsion.