Dmitry Ivanovich Mendeleev (1834–1907), a well-known Russian scientist more than a hundred and fifty years ago, published another of his discoveries. He found that the chemical behavior of elements depends on atomic weight. Based on this time limit law, he was able to create a clear system of chemical elements. This created a color chart that still hangs in almost every chemistry classroom. If you have consistently remembered the markings of the elements and you have a good memory, then no doubt you will excel in this test!