The bond order of ${\mathrm{N}}_2$ molecule is 

The bond order of N2 molecule is 3. To understand this, we need to calculate the bond order by using molecular orbital theory.

Bond order is defined as the difference between the number of bonding electrons and antibonding electrons, divided by 2. It is calculated using the following formula:

Bond Order = (Number of bonding electrons - Number of antibonding electrons) / 2

Now, let's look at the bond order of N2 step by step:

Step 1: Determine the Electron Configuration of N2

For a nitrogen molecule (N2), the total number of electrons is 14, as each nitrogen atom contributes 7 electrons. According to molecular orbital theory, the electrons are filled in the molecular orbitals in the following order:

• σ_1s (2 electrons)
• σ_1s∗ (2 electrons)
• σ_2s (2 electrons)
• σ_2s∗ (2 electrons)
• π_2p (4 electrons)
• π_2p∗ (2 electrons)

Step 2: Identify Bonding and Antibonding Electrons

In this case, the bonding electrons are those that occupy bonding molecular orbitals (σ and π), while antibonding electrons occupy the antibonding molecular orbitals (σ∗ and π∗).

From the electron configuration of N2:

• Bonding electrons: 10 (2 in σ_1s, 2 in σ_2s, 4 in π_2p)
• Antibonding electrons: 4 (2 in σ_1s∗, 2 in π_2p∗)

Step 3: Calculate the Bond Order of N2

Now, applying the formula to calculate the bond order of N2:

Bond Order = (10 - 4) / 2 = 6 / 2 = 3