Answer the question on the basis of the passage given below:

Molecular nitrogen is very little reactive chemically. During lightning discharge, atmospheric nitrogen and oxygen combine to form nitric acid which also combines with oxygen to form nitrogen dioxide. Both \(NO\) and \(NO_2\) constitute smog which is very poisonous. It can cause a burning sensation in the eyes and adversely affect the respiratory system.

Molecular nitrogen is very little reactive since it has:

high bond order

The correct answer is option 1. high bond order.

The reactivity of molecular nitrogen (\(N_2\)) is attributed to its unique molecular structure and high bond order. Let's explore this in more detail:

1. Molecular Structure: In \(N_2\), two nitrogen atoms are bonded together by a triple bond. The triple bond consists of one sigma (\(\sigma\)) bond and two pi (\(\pi\)) bonds. The arrangement of the bonds can be represented as \(\sigma\) and \(\pi\)-bonds:

The triple bond involves a strong sigma bond (head-on overlap of orbitals) and two pi bonds (sideways overlap of orbitals). This results in a highly stable and rigid molecular structure.

2. High Bond Order: Bond order is a measure of the number of chemical bonds between two atoms in a molecule. In the case of \(N_2\), the bond order is 3, indicating a triple bond. A higher bond order implies stronger bonding forces and greater stability. The high bond order in \(N_2\) is due to the presence of the triple bond, which consists of a sigma bond and two pi bonds.

3. Triple Bond Stability: The triple bond in \(N_2\) is strong, and breaking it requires a significant amount of energy. The electrons involved in the triple bond are tightly held between the two nitrogen atoms, contributing to the overall stability of the molecule.

4. Limited Reactivity:  Because of its stable triple bond, molecular nitrogen is relatively unreactive under normal conditions. Nitrogen gas makes up about 78% of Earth's atmosphere, and its unreactive nature contributes to its inert behavior in many chemical processes.

5. Activation Energy: To make nitrogen more reactive, significant energy (such as high temperature and pressure) is often required to break the triple bond. This process is known as nitrogen fixation and is essential for converting atmospheric nitrogen into forms that can be utilized by living organisms.

In summary, the high bond order associated with the triple bond in \(N_2\) contributes to its stability and limited reactivity under normal conditions. While this stability is beneficial for maintaining the inert nature of nitrogen gas in the atmosphere, it also requires special conditions to activate nitrogen for certain chemical transformations, such as those involved in industrial processes or biological nitrogen fixation.