who changed the periodic table to atomic number
History of the periodic table In 1914, a year before he was killed in action at Gallipoli, the English physicist Henry Moseley found a relationship between the X-ray wavelength of an element and its atomic number. He was then able to re-sequence the periodic table by nuclear charge, rather than by atomic weight. Before this discovery, atomic numbers were sequential numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers were in fact based upon experimental measurements.
History of the periodic table The Russian chemist Dmitri Mendeleev was the first scientist to make a periodic table similar to the one used today.[citation needed] Mendeleev arranged the elements by atomic mass, corresponding to relative molar mass. It is sometimes said that he played 'chemical solitaire' on long train journeys, using cards with various facts about the known elements.[11] On March 6, 1869, Mendeleev gave a formal presentation, The Dependence Between the Properties of the Atomic Weights of the Elements, to the Russian Chemical Society. In 1869, the table was published in an obscure Russian journal and then republished in a German journal, Zeitschrift fÃ¼r Chemie.[12] In it, Mendeleev stated that: