With some practice, you’ll be able to create Lewis structures for almost any molecule. Use the procedure below as a guide.
Let's take nitromethane (CH₃NO₂) as an example. The condensed structure is shown on the left, and your goal is to draw the corresponding Lewis structure on the right.
For negative charges add the corresponding number of electrons, for positive charged atoms subtract electrons.
In the case of nitromethane, since the molecule is neutral, we do not need to adjust.