Final answer:
Zinc's most common ionic charge in compounds is +2, which aligns with its tendency to form Zn+2 ions, balancing out negatively charged groups like CO3 with a -2 charge.
Step-by-step explanation:
The most likely charge of zinc in an ionic compound is +2. This is because zinc typically loses two electrons to form a cation with a +2 charge in its ionic compounds, such as in zinc carbonate (ZnCO3) where CO3 carries a negative 2 charge. To maintain a neutral overall charge in the compound, the +2 charge of zinc balances the -2 charge of the CO3 group.