what do these two changes have in common? rust forming on a metal gate using polish to remove tarnish from a…

what do these two changes have in common? rust forming on a metal gate using polish to remove tarnish from a silver spoon select all that apply. both are only physical changes. both are chemical changes. both are caused by heating. both are caused by cooling.
Answer
Brief Explanations:
Rust forming on a metal gate is a chemical reaction between iron in the metal and oxygen in the air, creating iron - oxide. Using polish to remove tarnish from a silver spoon involves a chemical reaction between the polish and the silver - sulfide (tarnish) on the spoon. Neither is a physical change, and neither is caused by heating or cooling.
Answer:
Both are chemical changes.