To draw the Lewis structure for nitrogen dioxide (NO2), we start by determining the total number of valence electrons in the molecule. Nitrogen (N) has 5 valence electrons, and each oxygen (O) has 6. Therefore, the total valence electrons in NO2 is:
5 (N) + 2 × 6 (O) = 17 valence electrons
Next, we place the nitrogen atom in the center, as it is the central atom, and connect it to the two oxygen atoms with single bonds:
At this stage, each single bond between the nitrogen and oxygen uses 2 electrons (one from nitrogen and one from oxygen). This accounts for 4 of the 17 valence electrons, leaving us with:
17 – 4 = 13 valence electrons
Now we distribute the remaining electrons. We’ll start by placing pairs of electrons around the oxygen atoms to complete their octets. Each oxygen requires 8 electrons to satisfy the octet rule:
– Place 6 electrons (3 pairs) around each oxygen atom. This accounts for 12 electrons (6 from one O and 6 from the other O):
13 – 12 = 1 electron left
We cannot place the remaining single electron on the oxygen atoms since they already have complete octets. Instead, we create a double bond between the nitrogen and one of the oxygen atoms to utilize that single electron.
This results in the following structure:
In this final structure, nitrogen is bonded to one oxygen with a double bond and to the other oxygen with a single bond. Now, let’s analyze the bonding:
- Single Bonds: 1 (N-O single bond)
- Double Bonds: 1 (N=O double bond)
- Triple Bonds: 0
- Unshared pairs of electrons on the central atom (N): 0
Therefore, in the Lewis structure of NO2, there is 1 single bond, 1 double bond, no triple bonds, and no unshared pairs of electrons on the nitrogen central atom.