The similarity between modern chemistry and alchemy (alchemy) is to create new things at the molecular level, but it is actually the task of nuclear physicists to create new elements. They use some cyclotron accelerators to blast out new elements and fill them into the periodic table as the winning fruit of chemists. Classical alchemy actually had the idea of elements and atoms, but it did not have rational thinking. For example, the Europeans in the Middle Ages believed that light, heavy, dry and wet were the basic physical properties, dry but light was fire and dry and heavy was soil. What is wet and light is gas and what is wet and heavy is water. Therefore, any substance is the result of different proportions of the four basic elements: water, fire, earth, and air, which is obviously different from the current concept of the world. At the same time, the understanding of the nature of matter in other civilizations is also between mystery and reason.
The starting point of rational thinking in modern chemistry is most likely to be discussed next.