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Nitrous oxide (N₂O) Lewis structure

16 valence electrons, linear

N N O + −
N₂O as the Lewis Structure Generator draws it: lone pairs as dots, nonzero formal charges circled.

Build N₂O step by step in the Lewis Structure Generator

What is the Lewis structure of N₂O?

Nitrous oxide, N₂O, has 16 valence electrons. Nitrogen is the central atom, joined by one N≡N triple bond and one N−O single bond. It carries one lone pair on the outer N and three on the O. Its formal charges are +1 on the central N and −1 on the O. N is AX₂: linear, and the molecule is polar.

Valence electrons in N₂O

Element Group Valence electrons Atoms Electrons
Nitrogen 15 5 2 10
Oxygen 16 6 1 6
Total 16

In one line: 2 × 5 + 6 = 16. Each atom brings the valence electrons its group gives it.

How to draw the N₂O Lewis structure

  1. Count the valence electrons. Valence electrons: each N 5 and O 6. 2 × 5 + 6 = 16.
  2. Choose the central atom. N goes in the middle. It is the least electronegative atom, χ 3.04 against 3.44 for O, but it appears more than once, so that alone does not settle it: with O in the middle the formal charges add up to 4, against 2 with N.
  3. Join the atoms with single bonds. Two single bonds use 4 electrons, leaving 16 − 4 = 12.
  4. Complete the outer atoms. Each outer atom takes enough lone pairs to reach eight: N 6 + O 6 = 12, leaving 12 − 12 = 0.
  5. Put the rest on the central atom. Nothing is left, so N gets no lone pair, and N now has 4 electrons round it.
  6. Make multiple bonds where needed. N has only 4 electrons, so two lone pairs move into the bonds, making an N≡N bond, and N now has 8.

Lone pairs and formal charges in N₂O

Atom Number Bonds Lone pairs Electrons round it Formal charge, V − N − B/2
N (central) 1 one triple bond and one single bond 0 8 5 − 0 − 4 = +1
N 1 one triple bond 1 8 5 − 2 − 3 = 0
O 1 one single bond 3 8 6 − 6 − 1 = −1

V is the atom’s valence electrons, N its nonbonding electrons and B its bonding electrons. The formal charges add up to 0, the molecule’s overall charge.

Minor resonance contributors to N₂O

Ranked by the same rules, the next best arrangements are valid Lewis structures that count for less in the real molecule.

N N O + −
+1 on the central N and −1 on the outer N. It puts negative charge on a less electronegative atom.

Shape and polarity of N₂O

Central atom N
VSEPR class AX₂
Electron geometry linear
Molecular geometry linear
Ideal bond angle 180°
Polarity, an estimate polar

Bonds of different polarity do not cancel in this shape.

N has two σ bonds and no lone pairs, two electron domains in all, so its electron geometry is linear. With no lone pairs, the molecular geometry is the same.

The VSEPR Molecular Geometry viewer turns the AX₂ shape in 3D, lone pairs included.

Work with N₂O