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Johann Dobereiner
Johann took note of how the elements were similar in some chemical related ways. He noticed that because of their similarity, could be grouped into groups of three. Dobereiner's findings led to the realization that in these groups of three, halfway between two of the elements, fell the atomic weight of the third element. Johann put forward the Law of Triads in the year 1829. -
Alexandre-Émile Beguyer de Chancourtois
This scientist organised the elements by increasing atomic weight and with similar elements lining up vertically on a spiral graph. This graph was arranged on a cylinder. He was the first to take note on the arrangement of the elements, in that similar elements seemed to occur at regualr intervals when they were in order according to their atomic weights. -
John Newlands
John Newlands created a table listing the elements in order of atomic weight. He proposed the Law of Octaves: an element behaves like the eighth one following it in the table. -
Lothar Meyer
Meyer classified half of the known elements of the periodic table in an abbreviated form and put it in a textbook. The elements were listed in order of atomic weight. After Mendeleev's periodic table was available, Lothar's was published. -
Dmitri Mendeleev
Dmitri, known as the 'father' of the periodic table in the modern world. What Mendeleev done was write out the names of all the discovered elements as well as having their properties and atomic weights on cards. In rows and columns, the cards were laid out. Like wat de Chancourtois and Newlands seen, Dmitri noticed the periodic repetition of chemical properties in certain elements. -
William Ramsay
Even though argon has a larger atomic weight than potassium, Ramsay said that this element should be inbetween the elements Chlorine and Potassium on the periodic table between elements chlorine and potassium and in a family with helium. -
Ernest Rutherford
Ernest's big moment came when he discovered the proton. After this discovery, it lead to the understanding that elements in the periodic table should be in order of their atomic number instead of their atomic weight.. -
Henry Mosely
The periodic law was modified by Mosely. He changed it around so that it could be read so properties of the elements varied periodically with their atomic number. He also determined the atomic number of each element. -
Glenn Seaborg
In the periodic table, transuranic elements are the elements that are after uranium. Neptium was produced by uranium being bombarded with neutrons. Elemnts deuterium and uranium produced another element called plutonium. After these discoveries, a new block in the periodic table was added consisting of these new elements. The block was known as the Actinides Series. 11 years later Seaborg was awarded a nobel prize for his discoveries.
