3.1 Chemistry developed out of interest in materials The ability to control fire allowed ancient people to prepare copper(7000 years ago) and iron (3200 years ago) for tools and Weapons 商代青铜器(铜锡合金3.1 Chemistry developed out of interest in materials The ability to control fire allowed ancient people to prepare copper (7000 years ago) and iron (3200 years ago) for tools and weapons. 商代青铜器(铜锡合金)