O2 will have a double bond in order for each atom to have 8 electrons
(Each dash is a shared pair of electrons)
- = single bond
- - = double bond
- - - = triple bond
So O2: O - - O
N2 needs a triple bond, so it’ll be: N - - - N
CO: C - - - O
SO2: O - - S - - O
You can figure out how many bonds you need, using a method called “NASU”, which stands for: Needed Available Shared Unshared
For example, let’s use oxygen, O2
Needed Available Shared Unshared
O needs 8 it has 6 8-6=2 6-2=4
O needs 8. it has 6. 8-6=2. 6-2=4
Using this, we can see that each oxygen atom has 2 electrons to share and will be left with 4 unshared pairs.
To get the number of bonds, you’ll add the results under shared and divide by 2
So, 2+2=4, 4/2=2
O2 will have 2 covalent bonds. This checks out with the Lewis Structure I drew. ✔️
