Final answer:
The metallic element used as a corrosion-resistant coating on the inside of cans is tin.
Step-by-step explanation:
The *metallic* element used as a *corrosion-resistant* coating on the *inside of cans* used for *packaging food, oil, and other substances* is **tin**. Tin is often used to coat steel cans to protect them from corrosion. When iron containers are coated with a thin layer of tin, it forms a protective oxide coating that prevents oxygen and water from reaching the underlying steel, thereby inhibiting corrosion.