17. Correct. The answer is false. Iron ore was heated in the presence of charcoal (not coal) and oxygen. Later with the industrial revolution coke was made from coal and used to create iron ore. The discovery of iron and its uses was crucial in the development of tools and weapons. This discovery also advanced the agricultural process with its many applications. It also expedited the killing/war process with the advancement of weapon technology, leading to better swords and eventually to cannons, guns and bullets.