CH4 Lewis Structure
Methane · Natural gas. The simplest hydrocarbon and a potent greenhouse gas.
The CH4 Lewis structure has 8 valence electrons, drawn as four bonds to hydrogen, with zero lone pairs in total. The central C is sp3 hybridized, which makes it a tetrahedral molecule with a bond angle of 109.5 degrees. CH4 is nonpolar: the bond dipoles are all the same size and the shape places them symmetrically around the central C, so they cancel exactly.
- 8 valence e−
- tetrahedral
- 109.5° bond angle
- sp3
- nonpolar
Calculated properties
| Total valence electrons | 8 |
|---|---|
| Bonding electrons | 8 (4 shared pairs) |
| Nonbonding electrons | 0 (0 lone pairs) |
| Lone pairs on C | 0 |
| Electron domains (steric number) | 4 |
| VSEPR notation | AX4 |
| Electron geometry | tetrahedral |
| Molecular geometry | tetrahedral |
| Bond angle | 109.5° |
| Hybridization | sp3 |
| Polarity | nonpolar |
| Formal charges | all zero |
| Resonance structures | none |
| Molar mass | 16.043 g/mol |
How to draw the CH4 Lewis structure
-
Count the valence electrons
Add up the outer-shell electrons every atom brings. That total is the budget for the whole structure - every line and every dot has to come out of it, and nothing may be added.
4 (C) + 4 x 1 (H) = 8 valence electrons -
Choose the central atom
Carbon is the central atom - it forms four bonds and is never terminal in these molecules.
-
Join everything with single bonds first
Every connection starts as one shared pair. Draw them all before worrying about double bonds - the arithmetic in the next step is what tells you where the double bonds have to go.
4 bonds x 2 = 8 electrons used, 0 left -
Work out how far short you are
Add up what every atom still needs to fill its shell - eight electrons for most atoms, two for hydrogen - minus what its single bonds already give it. Compare that with the electrons you have left. The difference decides everything that follows.
needs 0, has 0, exactly enough -
Check the central atom
C ends up with a full octet. Every electron in the budget is now placed.
C: 8 bonding + 0 nonbonding = 8 -
Check the formal charges
Formal charge is valence electrons, minus lone-pair electrons, minus the number of bonds. Every atom here comes out at zero, which is the sign of a good structure.
all formal charges = 0 -
Work out the shape
Count the electron domains on C: 4 bonded groups. A double or triple bond still counts as one domain, because it points in one direction. That gives tetrahedral electron geometry; ignore the lone pairs and the atoms themselves sit in a tetrahedral arrangement.
steric number 4 -> sp3 -> tetrahedral, bond angle 109.5 -
Decide whether it is polar
The bond dipoles are all the same size and the shape places them symmetrically around the central C, so they cancel exactly.
dipoles cancel -> nonpolar
Is CH4 polar or nonpolar?
CH4 is nonpolar. The bond dipoles are all the same size and the shape places them symmetrically around the central C, so they cancel exactly.
| Bond | Electronegativity difference | Character |
|---|---|---|
| C–H | 0.35 | nonpolar covalent |
Common questions
How many valence electrons does CH4 have?
CH4 has 8 valence electrons. 8 of them are in bonds and 0 sit in lone pairs.
What is the molecular geometry of CH4?
CH4 is a tetrahedral molecule. The central C has 4 bonded groups, a steric number of 4, which gives tetrahedral electron geometry and a tetrahedral molecule.
What is the bond angle in CH4?
The bond angle in CH4 is 109.5 degrees. That is the ideal tetrahedral angle, and nothing distorts it here.
What is the hybridization of CH4?
The central C in CH4 is sp3 hybridized. Steric number 4 means 4 orbitals have to be mixed, which is exactly what sp3 gives you.
Is CH4 polar or nonpolar?
CH4 is nonpolar. The bond dipoles are all the same size and the shape places them symmetrically around the central C, so they cancel exactly.