Development of the Modem Periodic Table

Research the life of a scientist, other than Mendeleev, who contribnted to the development of the modem periodic table of elements. Write a brief biography of this person and detail his or her scientific accomplishments. 

Many scientists contributed to the development of the modem Periodic Table. One of them was the Russian chemist Mendeleev. In 1869 he arranged the elements that were then known in a table very similar to the one in use today. He realized that gaps should be left for elements that had not yet been discovered, and even went so far as to predict the properties of several of these elements. Rubidium b an alkali metal that lies below potassium in Group I. Here is some data for Group I ... 

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