Numford
Lewis structure

Lewis structure of N₂

10 valence electrons. One N≡N triple bond, with one lone pair on N.

NN
  • N

N₂Nitrogen

Linear

Each N: 1 sigma bond, 1 lone pair

i

Two atoms always lie on a line. Hybridisation of an atom in a two atom molecule is a count of its sigma bonds and lone pairs; many books do not ask it.

  • Hybridisationsp
  • Polaritynon-polar
  • Bond order3

Lewis structure

10 valence electrons
NN

Formal charges: none

Why this shape

  1. Each N has 5 valence electrons. It uses three in one triple bond to N, so two are left as one lone pair.
  2. Steric number = one sigma bond + one lone pair = 2, so each N is sp hybridised. A double or triple bond counts once: only its sigma bond uses a hybrid orbital.
  3. Two electron pairs point in opposite directions, along a line (linear electron geometry). With only two atoms, the molecule itself is a straight line.
  4. Two atoms always lie on a straight line, so there is no bond angle.
  5. Both atoms are the same, so the bond is non-polar.

Molecular orbitals

14 electrons
3bond order
diamagnetic

(Nb − Na) / 2 = (10 − 4) / 2

1s1s2s2s2p2pσ1sσ*1sσ2sσ*2sπ2pσ2pzπ*2pσ*2pzN atomMoleculeN atomEnergy

σ1s² σ*1s² σ2s² σ*2s² (π2px² = π2py²) σ2pz²

Working

How to draw it

  1. Count the valence electrons: 2 × N 5 = 10 valence electrons, 5 pairs.
  2. Join the atoms with single bonds: the N atoms to each other and the H atoms around them.
  3. Give each outer atom lone pairs until it has an octet (H needs only two electrons), then put any electrons left over on the central atom.
  4. Where an atom is still short of an octet, turn a lone pair of its neighbour into a shared pair: that makes a double or triple bond.
  5. Result: one N≡N triple bond, with one lone pair on N.
  6. Formal charge = valence electrons − lone pair electrons − number of bonds. Here: none.

Class 11, Chapter 4 Chemical Bonding and Molecular Structure.

Questions

Lewis structure of N2: quick answers

How many valence electrons are in N2?

2 × N 5 = 10 valence electrons, 5 pairs.

What are the formal charges in the Lewis structure of N2?

Every atom has a formal charge of zero.

How many lone pairs are in the Lewis structure of N2?

2 in all, 1 of them on the central N.

Try any molecule