While cleaning out the garage, duane found his old bicycle. some of the paint had worn off, exposing the iron frame inside. duane noticed that parts of the iron frame had become reddish-brown and rough and that parts were flaking off. what happened to duane's old bicycle? a oxygen from the humid air chemically reacted with the iron in the frame, creating rust, a new substance with different properties. b oxygen from the humid air physically reacted with the top layer of iron, wearing it away to expose the natural rust underneath. c the circulating air in the garage deposited a layer of rust on the iron frame. d the iron in the frame naturally decomposed into rust without any reaction.