Question

Nitrogen molecule is chemically less reactive because of its:
A. Small atomic energy
B. High dissociation energy
C. High electronegativity
D. Stable electronic configuration

Answer 1

Hint :Nitrogen belongs to group $15$ of the periodic table. The two nitrogen atoms in a molecule are joined by the triple bond ( $N\equiv N$ ). We will see the reactive nature of the nitrogen and its reaction in the room temperature.

Complete Step By Step Answer:
Dinitrogen $N2$ is formed by sharing three electron pairs between two nitrogen atoms. Triple bond is formed by the two nitrogen atoms. The size of the nitrogen atom is quite small and therefore the bond length is very small ( $109.8pm$ ).
Nitrogen is a more electronegative element and hence its bond strength is also large. As a result, the energy of bond dissociation energy becomes very high at room temperature ( $946$ Kj/mol). It means a large amount of energy is required to break a nitrogen molecule.
 Such large energy is not present at room temperature under normal conditions. Hence the reactivity and reactive nature of the nitrogen becomes very low.
Therefore, we can conclude that nitrogen remains almost inert at room temperature because of its high dissociation energy.
Hence, the correct option is B. High dissociation energy.

Note :
The reactivity of any element or its compound depends on the bond dissociation energy. The compound or molecules whose bond dissociation molecule will be low, can easily cleave their bond. The more rapidly old bonds are cleaved the faster are the new bonds formed and reaction proceeds with great speed.