What is an electron configuration of a nitrogen molecule?

1 Answer
Aug 24, 2016

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

book.transtutors.com

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

The result is

img1.mnimgs.com

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#