Question

Among the following, the species having see-saw shape is/are

• A. SF$_4$
• B. XeF$_4$
• C. ClF$_4^-$
• D. ClF$_4^+$

Hint:

See-saw geometry always comes from AX$_4$E type species (one lone pair in trigonal bipyramidal geometry).

Answer 1

The Correct Option is A, C

Step 1: Identify electron pair geometry.
A see-saw shape corresponds to a trigonal bipyramidal electron geometry with one lone pair (AX$_4$E).
Step 2: Analyzing each species.
(A) SF$_4$: S has 5 electron pairs (AX$_4$E) → see-saw → correct.
(B) XeF$_4$: square planar (AX$_4$E$_2$) → not see-saw → incorrect.
(C) ClF$_4^-$: AX$_4$E$_2$ (octahedral with 2 lone pairs) → square planar → incorrect.
(D) ClF$_4^+$: AX$_4$E (five electron pairs) → see-saw → correct.
Step 3: Conclusion.
SF$_4$ and ClF$_4^+$ show see-saw geometry.