Final answer:
The molecular geometry for an sp3d hybridized atom with one lone pair of electrons is a seesaw shape.
Step-by-step explanation:
The molecular geometry around an atom that is sp3d hybridized and has one lone pair of electrons is seesaw. This is derived from the trigonal bipyramidal electron-pair geometry that is characteristic for sp3d hybridization. When one lone pair is present, the molecular structure alters to minimize repulsion and takes on a seesaw shape. This is due to the fact that lone pairs occupy more space than bonding pairs, which leads to the arrangement of atoms in a way that reduces electronic repulsion and creates a stable structure.