Question

In a compound, such as CH3OH, how determine which is the central atom?

Answer 1

Answer:

Choose the least electronegative atom other than H.

Explanation:

A Lewis structure consists of terminal atoms and one or more central atoms.

H can be only a terminal atom because it can form only one bond.

So the central atom must be either C or O.

The central atom is the less electronegative atom: C.

So, start the Lewis structure with a central C atom.

Then attach an O atom to get C-O.

Finally, attach the H atoms.

The condensed formula often gives you a clue where they go.

The formula CH₃OH implies that there are 3 H atoms on C and one on O.

The connectivity of the atoms is then as in the diagram below.