In VSEPR theory, what is the relative repulsion strength?

In VSEPR (Valence Shell Electron Pair Repulsion) theory, the relative repulsion strengths among electron pairs surrounding a central atom determine the geometry of a molecule. Lone pairs are considered to exert a stronger repulsive force compared to bonded electron pairs. This is because lone pairs are localized in space and occupy more volume, which leads to greater repulsion.

Multiple bonds consist of more than one shared pair of electrons, which also increases their repulsion compared to single bonds, although not as strongly as that from lone pairs. Thus, multiple bonds exert greater repulsion than single bonds due to their increased electron density.

This hierarchy of repulsion strength is crucial for predicting molecular geometry as it helps determine the angles and arrangement of the atoms around the central atom. Therefore, the correct ordering of repulsion strength in VSEPR theory places lone pairs at the top, followed by multiple bonds, and finally single bonds, making the first choice the correct one.