What is an electron configuration of a nitrogen molecule?

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

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 ##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##