In this example, we draw the Lewis structure for HCN, which is a molecule with multiple bonds. Our first step is to sum the valence electrons. We have one hydrogen atom with one valence electron, one carbon atom with four valence electrons, and one nitrogen atom with five valence electrons. Since this is a neutral molecule, we do not need to adjust our number of valence electrons to take into account a charge. Adding these together, we have a total of ten valence electrons. Our second step is to draw the structure with only single bonds. This is an organic molecule containing carbon. The formulas for organic molecules can be written to give you an idea of how to draw them. For HCN, we'll connect these three atoms in a row with single bonds, just as the formula shows. By creating these two single bonds, we've used up four of our 10 electrons, so we have six electrons left. Our third step is to satisfy the octet rule by adding lone pairs, starting with the peripheral atoms. Hydrogen follows the duet rule, so it is already satisfied with just a single bond. But nitrogen follows the octet rule. With one single bond, nitrogen currently has two electrons, so it wants six more electrons. We can put our last six electrons on nitrogen to satisfy the octet rule. However, now we've run out of electrons and carbon is not yet satisfied. Carbon wants eight electrons, but it currently has just four. So we can use two of the lone pairs we put on nitrogen to create a triple bond with carbon. This satisfies carbon with eight electrons and keeps nitrogen satisfied with its eight electrons. Now all of our atoms are satisfied according to the octet and duet rules. This is our Lewis structure for HCN.