The common element in all these compounds is zinc (Zn).

Zinc Chloride (ZnCl2) is a chemical compound containing zinc and chloride ions. It is commonly used as a catalyst in various chemical reactions.

Zinc Sulfate (ZnSO4) is a chemical compound containing zinc and sulfate ions. It is used as a dietary supplement and in the production of various products including fertilizers and medications.

Zinc Nitrate (Zn(NO3)2) is a chemical compound containing zinc and nitrate ions. It is commonly used in the production of pigments, catalysts, and other chemical processes.