The molecule in which an atom is associated with more than 8 electrons is known as hypervalent molecule and less than 8 electrons is known as hypovalent molecule. All hypervalent molecules must have `ppi-dpi` bonding but the molecules having back bonding back boding need not to have always `ppi-dpi` bondin.
Q.Which of the molecule is not hypovalent but complete its octet:

Options

A. `AlI_(3)`
B. `AlCl_(3)`
C. `AlBr_(3)`
D. `AlF_(3)`

Answer

C

Explanation

`AlF_(3)` is ionic compound, hence `Al^(3+) and F^(-)` both have complete octet, rest compounds do complete, their octet