Question

Boron cannot form which of the following anions?

• A. $B(OH{)}_4^{-}$
• B. $B{O}_2^{-}$
• C. $B{F}_6^{3-}$
• D. $B{H}_4^{-}$

Answer 1

The correct option is C $B{F}_6^{3-}$

Because of the non-availabilty of d-orbitals , boron is uanble to expand its octet. Hence the maximum covalence of boron cannot exceed $4$. Thus option (C) is correct.