question: What will cause metal to turn orange?
choices.text: Exposure to nitrogen higher ultraviolet  radiation thermal expansion Exposure to hydrochloric acid antigens that cause allergy a surface not sterilized Exposure to helium and carbon Exposure to oxygen and water
choices.label: A B C D E F G H
fact2: Iron rusts in the presence of oxygen and water.
combinedfact: oxygen and water will cause metal to turn orange
formatted_question: What will cause metal to turn orange? (A) Exposure to nitrogen (B) higher ultraviolet  radiation (C) thermal expansion (D) Exposure to hydrochloric acid (E) antigens that cause allergy (F) a surface not sterilized (G) Exposure to helium and carbon (H) Exposure to oxygen and water