Question

What is an electron configuration of a nitrogen molecule?

Answer 1

The electron configuration of `"N"_2` is
`(σ1s)^2(σ^"∗"1s)^2(σ2s)^2(σ^"∗"2s)^2(π2p_x)^2(π2p_y)^2(σ2p_z)^2`

Explanation:

The molecular orbitals of `"N"_2` are formed by overlapping the atomic orbitals of the `"N"` atoms.

The new molecular orbitals are formed as follows:

• The `1s` orbitals form a bonding `σ1s` and an antibonding `σ"*"1s` MO.
• The `2s` orbitals form a bonding `σ2s` and an antibonding `σ"*"2s` MO.
• The `2p` orbitals directed along the internuclear axis form a bonding `σ2p_z` and an antibonding `σ"*"2p_z` MO.
• The `2p_x` and `2p_y` orbitals from each atom form bonding `π2p_x` and `π2p_y` bonding MOs and antibonding `π"*"2p_x` and `π"*"2p_y` MO.

The relative energy levels of the orbitals are

Each `"N"` atom contributes seven electrons, so we use the Aufbau Principle to fill the MOs starting at the lowest level.

The result is

Thus, the electron configuration of `"N"_2` is

`(σ1s)^2(σ^"∗"1s)^2(σ2s)^2(σ^"∗"2s)^2(π2p_x)^2(π2p_y)^2(σ2p_x)^2`