The ionic formula for zinc and sulfur is ZnS. Here's how we arrive at that:

* Zinc (Zn) is a transition metal that forms a +2 ion (Zn²⁺).

* Sulfur (S) is a nonmetal that forms a -2 ion (S²⁻).

Since the charges are equal and opposite, they cancel each other out, resulting in a simple 1:1 ratio in the formula.