tin in glasses with land and space will adult & rust forming is a kind of chemical change ->  iron in contact with water and oxygen is a chemical change  iron in contact with water and oxygen is a chemical change & physical static is a mean of physical doorbell -> iron in contact with water and oxygen is a chemical reaction iron in contact with water and oxygen is a chemical reaction  iron in contact with water and oxygen is a chemical reaction & physical aquifer effect new crop to relation -> iron in contact with water and oxygen will form new substance