Question Description:

Do you have iron cans or aluminum cans first?

Analysis:

The weak acid in aluminum cans stored for a long time will dissolve and exist in the form of aluminum ions, which are harmful to people's health and can hinder the development of people's central nervous system, thus causing mental retardation. However, aluminum has good ductility and is easy to grind thin, so the early cans were made of aluminum. With the development of technology, iron can also be ground very thin, which makes it possible to make cans, and the price is relatively low. The ferrous ions formed by iron dissolved in weak acid are beneficial to human body, so iron has become a good material for making cans. < P > There are aluminum cans before iron cans, and beer metal cans have been produced in the United States since the early 193s, but this three-piece can cannot be called cans, because that kind of iron is not only thick, but also.