Li2O
Fe(NO3)3
Al2O3
CuCl2
ZnSO4
All you have to do here is make sure your charges are balanced when you write the compound. For example, Iron (III) has a +3 charge, and nitrate has a -1 charge. You need 3 nitrates to match that charge, hence Fe(NO3)3.
Answer:
Moving Across a Period
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons