Methane contains a central carbon atom joined to four hydrogens by single bonds. Carbon has no lone pairs, so the four bonding domains spread into a tetrahedral arrangement.
Carbon contributes four valence electrons and four hydrogen atoms contribute four more. Every available electron is used in one of the four C–H bonds. Carbon reaches an octet and each hydrogen reaches a duet without any formal charge.
How to draw the CH4 Lewis structure
Count 8 valence electrons.
Add 4 from carbon and 1 from each hydrogen.
Place carbon in the center.
Hydrogen is terminal and can form only one bond.
Draw four C–H bonds.
The four single bonds use all 8 electrons.
Check the octet and duet rules.
Carbon sees eight bonding electrons and each H sees two.
Confirm formal charges.
Every atom has formal charge zero.
Formal charges
Carbon is assigned half of the eight bonding electrons, which equals its four valence electrons. Each hydrogen is assigned one electron from its bond. No charge separation is required.
Geometry and polarity
Four equivalent bonding domains produce a tetrahedral geometry. The individual C–H bonds have small polarity, but the symmetric three-dimensional arrangement cancels the bond dipoles, so CH4 is nonpolar.
Common mistakes
Adding lone pairs to carbon after all eight electrons have already been used.
Drawing methane as a flat square; its actual geometry is tetrahedral.
Using C=H double bonds. Hydrogen never forms a conventional double bond.
Counting ten or twelve electrons instead of eight.
Frequently asked questions
Why does CH4 have no lone pairs?
All four of carbon's valence electrons participate in four shared bonding pairs.
Is methane polar?
No. Its tetrahedral symmetry cancels the small C–H bond dipoles.
What is carbon's hybridization in methane?
Carbon is conventionally described as sp³ hybridized.