 Okay so let's do some examples. We'll start with nitrogen gas and we'll go through the same steps that we learned in the last video. So the first thing is to total up the valence electrons. Now we're going to do nitrogen gas in 2. So we have 2 nitrogen atoms, nitrogen is group 5, we know it has 5 valence electrons, so with 2 nitrogen atoms we must have 10 valence electrons in total. So when we get to the end and we've finished our structure we want to have used up 10 valence electrons in the structure. The second step is to look at how many bonds each atom is able to form. Nitrogen group 5, valence of minus 3, so it forms 3 bonds. So each of these nitrogen atoms is going to want to form 3 bonds. Since there are only 2 atoms, each one of them must form 3 bonds with the other. So I'm going to draw out the skeleton of my molecule like that. This way each nitrogen is forming 3 bonds. First I check whether the atoms have a full outer shell. Each nitrogen has formed 3 bonds. There are 2 electrons in each bond, so that's a total of 6 electrons for each nitrogen. But it wants 8 for a full outer shell, so it does not have a full outer shell. So if each has 6 and it needs 8 I need to give each nitrogen an extra 2 electrons. So I'm going to do that by giving each nitrogen a lone pair of electrons, a pair of non-bonding electrons. So each of them now has 6 bonding electrons and 2 non-bonding electrons, which is a total of 8. My final step is to check that I've used up the right number of electrons. So I started off with 10 from the 2 nitrogen atoms. If I count up the electrons that I've used up I have 6 bonding electrons plus 4 non-bonding electrons, which is 10 altogether. So the electrons in my structure equal the number of valence electrons that I started with. So that's my final structure.