Question

Maximum covalency of nitrogen is:
A. $4$
B. $5$
C. $3$
D. $6$

Answer 1

Hint:
Here the definition of the covalency of nitrogen and electronic configuration should be known and then we can decide the maximum number of covalencies. Count the number of electrons present in the valence shell, then count the number of electrons required to complete the octet state, that will be the covalency of that atom.

Complete step by step solution
The covalency of the atom changes as per the number of atoms in the valence shell. In the periodic table the s-block elements have one and two electronic configurations. The s-block elements have the ability to lose electrons. To form the ionic bond. p-block elements have the ability to share electrons by sharing they form covalent bonds rather than ionic bonds. They have negative valency (attract electron) and it varies from atom to atom based on the number of valence electrons and the ability to donate electrons (electronegativity). In d-block the wide range of oxidation states is seen because of five sub-shell in the d-orbital which help electrons of transition metal to jump from one state to another in the sub-orbitals known as d-d transition.
Covalency of the atom is the number of electrons that are present in the valence shell which take part in covalent bond formation by getting exchanged with another atom. The electronic configuration of nitrogen is \[\left[ {He} \right]{\rm{ }}2{s^2}2{p^3}\]. It has 7 electrons and the distribution of electrons we can say that the number of valence electrons are 5, i.e. two \[2s\] and three \[2p\] valence electrons. By sharing the three \[2p\] electrons, nitrogen can form three covalent bonds. So we can say that nitrogen requires three more electrons in order to complete its octet. So it’s covalency is three. For example,\[N{H_3}\]. But still the nitrogen atom has a lone pair of electrons from \[2s\] orbital. By donating these two electrons from a lone pair, it can form one bond. For example,\[NH_4^ + \]. Therefore, nitrogen can form four bonds.

Hence, the correct option is (C).

Note:
The covalency of the atoms will decide which type of bond and number of bonds the atom will form (ionic or covalent).