Methylene (CH₂) Lewis structure
6 valence electrons, bent
Build CH₂ step by step in the Lewis Structure Generator
What is the Lewis structure of CH₂?
Methylene, CH₂, has 6 valence electrons. Carbon is the central atom, joined by two C−H single bonds. It carries one lone pair on the central C. Every formal charge is zero. C is AX₂E₁: bent, with an ideal bond angle of 120°, and the molecule is polar.
Valence electrons in CH₂
In one line: 4 + 2 × 1 = 6. Each atom brings the valence electrons its group gives it.
How to draw the CH₂ Lewis structure
- Count the valence electrons. Valence electrons: C 4 and each H 1. 4 + 2 × 1 = 6.
- Choose the central atom. C is the only atom other than H, and H is never in the middle, since it holds only two electrons and so makes one bond.
- Join the atoms with single bonds. Two single bonds use 4 electrons, leaving 6 − 4 = 2.
- Complete the outer atoms. Every outer atom is H, and its one bond already gives it the two electrons it holds. 2 remain.
- Put the rest on the central atom. The 2 left go on the central atom as one lone pair on C, and C now has 6 electrons round it.
- Make multiple bonds where needed. C is left with 6 electrons. Every atom bonded to it is H, which has no lone pair to turn into a second bond, so C stays short, one of the known exceptions to the octet rule.
Lone pairs and formal charges in CH₂
| Atom | Number | Bonds | Lone pairs | Electrons round it | Formal charge, V − N − B/2 |
|---|---|---|---|---|---|
| C (central) | 1 | two single bonds | 1 | 6 | 4 − 2 − 2 = 0 |
| H | 2 | one single bond | 0 | 2 | 1 − 0 − 1 = 0 |
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.
Shape and polarity of CH₂
| Central atom | C |
|---|---|
| VSEPR class | AX₂E₁ |
| Electron geometry | trigonal planar |
| Molecular geometry | bent |
| Ideal bond angle | 120° |
| Polarity, an estimate | polar |
The bent shape leaves the bond dipoles unbalanced.
C has two σ bonds and one lone pair, three electron domains in all, so its electron geometry is trigonal planar. Counting only the bonded atoms, the molecular geometry is bent.
The VSEPR Molecular Geometry viewer turns the AX₂E₁ shape in 3D, lone pairs included.
Notes on the CH₂ Lewis structure
- Methylene is a carbene, and this is its singlet form, with carbon’s two nonbonding electrons paired in one lone pair. Its ground state is the triplet, about 38 kJ/mol lower, with those two electrons unpaired in separate orbitals, which no single Lewis structure shows.
Work with CH₂
- Lewis Structure Generator: CH₂ built step by step, with every formal charge worked out
- VSEPR Molecular Geometry: every VSEPR shape in 3D, with its bond angles
- All 78 Lewis structures: valence electrons, resonance, shape and polarity in one table