Jill formed ionic compounds using the index cards she combined sodium and zinc to form the compound na2zn is this a possible a ionic compound and why

No. Zn can only have oxidation states of 1+ or 2+. For this compound to be able to exist, the Zn would have to have an oxidation state of 2- to counteract the 2+ from the 2 sodium ions. Sodium ions each have a +1 charge, so the 2 sodium ions would carry a +2 charge. In order for the compound to exist, the net charge between the 2 sodium and 1 zinc atoms would need to be 0.