Great question! You actually can use o-, m-, and p- even if the two substituents are different, as long as there are only two total groups on the benzene ring. Once there are more than two substituents, we switch to numbering the ring instead.

We have a video that will help you learn how to name alkanes this is best because you'll be tested on how to name alkanes on exams. 

Yes that's correct the benzene would instead be the parent chain. Parent chain goes to the longest carbon chain. 

In this resonance structure, we’re not adding or removing atoms, just moving electrons (lone pairs and pi bonds). So if there’s a double bond between carbon and oxygen to start, that carbon doesn’t have a hydrogen in the first place.

The resonance structure on the right still has the same number of atoms, just a different arrangement of electrons. And that carbon does have four bonds total: three to carbon atoms and one to oxygen. But when the pi electrons move onto the oxygen, carbon loses electron density, so it ends up with a formal positive charge. You can see this movement of electrons and where they went in purple.

After you watch this I highly recommend the next two videos they will help you practice these concepts even more:

Study With Us 

Practice Problem: Drawing All Resonance Forms That Stabilize a Carbocation

That would give nitrogen 4 bonds and no formal charge, which violates the octet rule and formal charge rules. If nitrogen is making 4 bonds (2 double bonds), it’s sharing 8 electrons, but nitrogen only has 5 valence electrons. Valid resonance structures share the same total number of electrons, same atom connectivity, and obey the octet rule.

The two resonance forms shown, where the double bond switches between oxygens are the only valid ones.

After you watch this I highly recommend the next two videos they will help you practice these concepts even more:

Study With Us 

Practice Problem: Drawing All Resonance Forms That Stabilize a Carbocation

Hey Daniella, The electrons are still there, what you'll notice as we move through Organic Chemistry is that the lone pairs won't always be shown but you will still be expected to know that they are there. It's like the hydrogens on Carbons that we saw aren't shown (this will be explained later on if you have gotten there yet) and it's a quicker way to draw structures. 

We don’t currently have a video on that topic, I’m so sorry about that. But you can get an instant explanation from our AI Tutor at any time. It’s designed to walk you through concepts step-by-step and is available 24/7.

We are so glad these videos have been helpful! Oh wow taking both Ochem 1 and 2 at the same time is intense!

I see you already upgraded to the Premium plan you'll find the drop in tutoring sessions here: https://chemmunity.com/calendar/agenda

Hey Paola,

The electrons are still there, what you'll notice as we move through Organic Chemistry is that the lone pairs won't always be shown but you will still be expected to know that they are there. It's like the hydrogens on Carbons that we saw aren't shown (this will be explained later on if you have gotten there yet) and it's a quicker way to draw structures. 

Joelle question 9 at 44:13 of the below video is another example of reactions of dienes.