Which of the following has a **see-saw** molecular geometry around the central atom?

VSEPR around the central S in $\mathrm{SF_4}$: S has 6 valence electrons, 4 are used in 4 S-F bonds, leaving 1 lone pair. **Total electron domains:** 5 (4 bond pairs + 1 lone pair) giving a trigonal-bipyramidal *electron* geometry but a **see-saw** *molecular* shape because the lone pair occupies an equatorial position. Compare: - $\mathrm{SF_6}$: 6 bond pairs, 0 lone pairs → octahedral. - $\mathrm{XeF_4}$: 4 bond pairs + 2 lone pairs → square planar (lone pairs axial). - $\mathrm{PF_5}$: 5 bond pairs + 0 lone pair → trigonal bipyramidal. See-saw is the shape you get from a trigonal bipyramid when you delete one equatorial vertex.