Q. The correct statement is
A) Aluminium has five valence orbitals.
B) Boron has a maximum covalency of four.
C) Beryllium has three valence orbitals.
D) Magnesium has a maximum covalency of four.
Explanation
[Solution from source] Boron has only 2s and three 2p orbitals in its valence shell, so it can form at most four bonds (as in BF₄⁻). Aluminium has 3s, 3p and vacant 3d orbitals, and beryllium has four valence orbitals, not three. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.