How to Find the Valence Electrons for CH4 (Methane)

To determine the number of valence electrons for CH4, the Methane molecule, we’ll use the Periodic Table. Organizing the Periodic Table by Group, skipping the transition metals, makes it clear how many valence electrons there are for each element in CH4.

--Valence Electrons by Group on Periodic Table--

Group 1: one valence electron
Group 2: two
Skip the Transition Metals
Group 13 (3A): three
Group 14 (4A): four
Group 15 (5A): five
Group 16 (6A): six
Group 17 (7A): seven
Group 18 (8A): eight*
*Helium only has two valence electrons even thought it is in Group 18 (8A).
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For CH4, we have a total of 8 valence electrons. C is in Group 14 (4A) and H is in Group 1. Therefore we have 4 + 1(4) = 8 for the Methane molecule.

Valence electrons are important because they are the electrons on the outside of an atom and are able to form chemical bonds. We consider them to be in the outer shell of an atom and they influence the chemical properties of an atom. When we draw a Lewis Structure for a molecule like CH4 we need to take the number of valence electrons for each atom into account.