The first metals that man learned to process and smelt were tin and copper, because they can be smelted in an ordinary fire. As a result of the alloy of copper and tin, bronze was obtained. Gold and silver were found in nuggets, from which jewelry was made. At the end of the second – beginning of the first millennium BC. people learned to work with iron. Iron is not found in nature in its pure form. It is mined from iron ore. At very high temperatures, people began to smelt iron with the help of special furnaces.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.