Final answer:
The electron and molecular geometry for a molecule with 6 bonding domains and a single lone pair is octahedral and square pyramidal, while for a molecule with 5 bonding domains and two lone pairs, it is trigonal bipyramidal and see-saw shaped.
Step-by-step explanation:
To determine the electron and molecular geometry of a molecule, we follow the VSEPR (Valence Shell Electron Pair Repulsion) theory.
a) For a molecule with 6 bonding domains and a single lone pair, the electron-pair geometry is octahedral (six regions of electron density) and the molecular structure is square pyramidal.
b) For a molecule with 5 bonding domains and two lone pairs, the electron-pair geometry is trigonal bipyramidal (five regions of electron density) and the molecular structure is a see-saw shape.