A gate made of painted iron is beginning to rest in areas where the paint has worn away why is the formation of rust considered a chemical change? A. oxygen in the air combines with the paint, forming a new compound that has the same properties as iron but a different arrangement of atoms.

B. Oxygen in the air combines with the exposed iron, forming a new compound that has properties different from iron.

C. The paint reacts with the iron beneath it and causes rust to form, changing the chemical properties of the iron.

D. The paint reacts with oxygen in the air and causes rust to form, changing the chemical properties of the iron.