Answer:
Henning Brand - 1649 (Discovered Phosphorus)
J. W. Dobereiner - 1829 ( Discopered Holegen Triad and Alkalin Metal Triad)
A. E. De Chancourtois - 1862 (First periodic table created)
John Newland - 1864 ( Published his own version of the periodic table and developed the Law of Octaves)
Dmitri Mendeleev - 1869 (Published his periodic table, eventually becoming the “father of the periodic table")
Lothar Meyer - 1870 (published his version of the periodic table (after Mendeleev))
William Ramsey - 1898 (Helped to establish the “zero” group (for “zero valency”) and predicted the future discovery of the element neon.)
Morris Travers - 1899 (Travers was Ramsay 's right hand man during the exciting years of the discovery of the noble gases and subsequently worked on the liquefaction of gases. Travers' book with the catchy title "The Experimental Study of Gases - An Account of the Experimental Methods Involved in the Determination of the Properties of Gases, and of the More Important Researches Connected with the Subject.")
Henry Moseley - 1913 (discovered the isotopes of elements. This discovery established that “the properties of the elements varied periodically with atomic number,” not atomic weight, which had been previously accepted under periodic law.)
