HISTORY OF PERIODIC TABLE

discovery of first element

1649

HENNIG BRAND discovered the first element PHOSPHORUS

Discovery of triads

1829

JOHANN DOBEREINER discovered the halogen triad and the alkali metal triad.

creation of first periodic table

1862

The first periodic table was created by A.E.BEGUYER DE CHANCOURTOIS. He assembled the table by transcribing a list of the elements positioned on a cylinder in terms of increasing atomic weight.

Law of Octavos

1864

JOHN NEWLANDS published his version of periodic table and proposed the law of octavos (by analogy with the seven intervals of the musical scale).

Father of periodic table

1869

RUSSIAN DMITRI MENDELEEV published his periodic table , eventually becoming the " father of the periodic table ". till this time 63 elements were discovered.

Another publisher of periodic table

1870

LOTHAR MEYER published his periodic table.

Discovery of argon

1895

LORD RAYLEIGH discovered ARGON , a new gaseous element that was chemically inert and didn't fit in the current groups. It was later suggested to place argon between chlorine and potassium .

Establishment of zero group

1898

WILLIAM RAMSEY helped to establish zero group ( for zero valency ) and predicted the future discovery of element neon.

Studies of alpha particles

1911

ERNEST RUTHERFORD created studies of alpha particles of heavy nuclei which led to the nuclear charge. A.VEN.BROEK established that the atomic weight of an element was approximately equal to the charge on an atom . This charge was later termed as atomic number .

Results of x-rays

1913

HENRY MOSELEY published results of the x-ray wavelenght of many elements which proved that the element are in order by atomic number.

Discovery of plutonium and transuranic elements

1940

GLENN SEABORG discovered plutonium and the transuranic elements from 92 to 104 . His findings represents the last (and the most ) recent changing to the periodic table .