Question

Which of the following elements can show covalencey greater than 4?
(a) Be (b) P (c) S (d) B

Answer 1

Answers: (b) P (c) S

Elements Be and B lie in the 2nd period. They can have a maximum of 8 electrons in the valence shell. In other words, they can have a maximum covalency of $\frac{8}{2}=4$
However, elements P and S have vacant d- orbitals in their respective valence shells and hence can accommodate more than 8 electrons in their respective valence shell in other words, they can show a covalency of more than 4.