And in fact, here's one other one. Instead of creating that pi bond, by placing those two balanced electrons into our pipeline here, we could have simply placed those two electrons on oxygen, and that would create another lewis dot structure. However, this structure has a negative charge on oxygen and a plus charge on the carbon, because we only have one, two, three bonds here, and we have 123-4567 electrons on the oxygen. So notice the following. We have two different lewis structures for formaldehyde, and in fact, this idea, this concept is called resonance. And these structures, lewis dot structures, are called resonant forms.