$1.$draw as many Lewis structures with the formula $C_2{H}_{3}ON$ as you can. All molecules must have closed shells, no formal charges, and different connectivity $($arrangement of atoms$).$

Hint: there are significantly more than $10$ and you need to show more than $10$ for full credit

$2.$choose $4$ of your molecules from above and identify all polar bonds.

$3.$now come up with $2$ molecules of the same formula that contain atoms with formal charge $($only $+1$ and $-1)$ and show how it is calculated for each.

$4.$What is the difference between those molecules that you made that contain all sigma bonds from those that also have pi bonds? $($if you don't have a structure with no pi$-$bonds, be sure to come up with at least one$)$