Molecular shape arrangement

[Angelina Tran 2F]

Hi!

can someone explain to me why when considering the arrangement, lone pairs are accounted for but for the shape, they are not?

[JadaArreola_2E]

Lone pairs are considered for the arrangement because of the positions of all the bonds, including both shared and lone pairs. The position is essential for looking at the polarity of the molecule. We do not look at lone pairs for the shape because we look at the atoms themselves, not the lone pairs as they do not effect angels of shared bonds when looking at the shape.

[606012329]

Electron arrangement is concerned with all of the electrons present, including those in atoms and those as lone pairs. The lone pairs impact the electron arrangement and especially the bond angles by causing repulsion. However, molecular shape is only concerned with that of the atoms, not lone pairs. It can give us an idea of bond angles but experimentation is required to know for sure.