What is the molecular geometry for methane?

Question

How do you know the molecular geometry of methane?

Answer 1

The answer given as tetrahedral is correct. The answer to how do you know the molecular geometry of methane requires further explanation.

Once you have the Lewis structure with C in the center with 4 H atoms bonded singly, you then see that there are 4 bonding pairs of electrons and no lone pairs of electrons on the central atom. This allows the H atoms to be separated from each other by the largest difference if they adopt a tetrahedral shape. This is most desirable since it leads to the most stable situation. In general chemistry, they usually provide you with a table of number of bonding pairs of electrons along with lone pairs on the central atom, and the table then tells you what the molecular geometry will be.

Answer 2

Methane is tetrahedral. The bonds to hydrogen are as far apart as possible with carbon in the middle.