Final answer:
A molecule with the general formula AX4E2 has six regions of electron density, forming an octahedral electron-pair geometry and resulting in a square planar molecular geometry due to the placement of the two lone pairs on opposite sides of the octahedron.
Step-by-step explanation:
According to VSEPR theory, the molecule with the general formula AX4E2 has six regions of electron density surrounding the central atom. These six regions adopt an octahedral electron-pair geometry, which represents the arrangement of all regions of electron density (bonding and lone pairs).
The molecular geometry of AX4E2 is determined by the positions of the atoms in space after accounting for the lone pairs. The lone pairs tend to occupy positions that minimize repulsion, and in AX4E2, the two lone pairs are located on opposite sides of the octahedron. This results in a square planar molecular geometry because the bonded atoms form a square, while the lone pairs are positioned above and below this square, not contributing to the shape perceived by the bonded atoms.
Thus, the correct answer to the provided question is (a) 6 regions; octahedral; square planar. This configuration minimizes repulsion between the two lone pairs and the bonding pairs, providing stable molecular structure.