Answer:
The common element is: Oxygen
Step-by-step explanation:
Potassium chlorate is an ionic molecule, having molecular formula KClO₃. It contains a potassium cation (K⁺) and a chlorate anion (ClO₃⁻). The chlorate anion is composed of a chlorine atom and three oxygen atoms.
Zinc nitrate is an ionic molecule, having molecular formula Zn(NO₃)₂. It contains a zinc cation (Zn²⁺) and a nitrate anion (NO₃⁻). The nitrate anion is composed of a nitrogen atom and three oxygen atoms.
Therefore, the common chemical element that can be found in both, potassium chlorate and zinc nitrate is oxygen.