Chemistry
Chemistry
Problem
Which molecular geometry is least likely to result from a trigonal bipyramidal electron geometry? a. Trigonal planar b. See-saw c. Linear d. T-shapedIntuitive explanation
Trigonal bipyramidal electron geometry has five electron domains arranged in space, but not all of them become bonding pairs—some are lone pairs. The key insight is that lone pairs occupy the equatorial positions (the "belt" of the trigonal plane) because they repel more strongly and need more room, while bonding pairs fill the axial positions. Depending on how many lone pairs you have, you'll get different molecular shapes, so think about which common geometries are impossible to build this way.
Intuitive explanation
Trigonal bipyramidal electron geometry has five electron domains arranged in space, but not all of them become bonding pairs—some are lone pairs. The key insight is that lone pairs occupy the equatorial positions (the "belt" of the trigonal plane) because they repel more strongly and need more room, while bonding pairs fill the axial positions. Depending on how many lone pairs you have, you'll get different molecular shapes, so think about which common geometries are impossible to build this way.