Question

Boron cannot form which one of the following anions?

Options

• \[\ce{BF^{3-}6}\]

• \[\ce{BH^{-}4}\]

• \[\ce{B(OH)^{-}4}\]

• \[\ce{BO^{-}2}\]

Answer 1

\[\ce{BF^{3-}6}\]

Explanation:

Because of the lack of d-orbitals, B cannot extend its covalency beyond 4 and so forms just \[\ce{BF^{-}4}\]. rather than \[\ce{BF^{3-}6}\]