Which one of the following elements is unable to form `MF_6^(2-)` ion?

Options

A. B
B. Al
C. Ga
D. In

Answer

A

Explanation

`because` 'B' has no vacant d-orbitals in its valence shell, so its valence shell, so it can't extend its covalencey beyond 4, i.e. 'B' cannot form the ion like `MF_(6)^(3(-))` i.e. `BF_(6)^(3(-))` .
Hence the correct option is (1)