On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing the periodic table. He ...

Dmitri Ivanovich Mendeleev was not the first to recognize the periodicity of the chemical elements or even to construct a primitive periodic table. He did go much further than his peers, however, in ...

At the middle of the 19th century, 63 chemical elements were known to science. Before Mendeleev’s discovery, attempts at arranging them in some logical way were made by Johann Doebereiner (1829), ...