Answer:
Li+, C4+, O2-, and then F- They're written in decreasing ionic size.
Step-by-step explanation:
Ionic size means the same thing as ionic radius. Furthermore, Ionic radius is the distance away from the central atom. Ionic radius increases going from top to bottom and decreases across the periodic table.
Lithium is in the 1st family/group with a charge of +1. So it has the biggest ionic radius.
Carbon is in the 4th family/group with a charge of +4. So it has a smaller ionic radius than Lithium.
Oxygen is in the 6th family/group with a charge of -2. So it has a smaller ionic radius than Carbon.
Lastly, Fluorine is in the 7th family/group with a charge of -1. So it has a smaller ionic radius than Oxygen.