Medium· Formal Charge (Formal Charge and its Applications)· +4 / −1
The correct formal charges on oxygen atoms numbered 2, 1 and 3 respectively are:
The structure is ozone. Oxygen 1 is the central atom: it has one lone pair, a double bond to oxygen 2 and a single bond to oxygen 3. Oxygen 2 has two lone pairs and oxygen 3 has three lone pairs.

