Periodic Table

Events

A.E.Beguyer de Chancourtois

1862

The first official attempt creating an ordering of the chemical elements was made by a French geologist in 1862, a man named A.E.Beguyer de Chancourtois. de Chancourtois made of the elements on a cylinder in terms of increasing the atomic weight. de Chancourtois was the first to recognise that the elemental properties reoccur every seven elements.

Dimitri Mendeleev

1869

In 1869, a Russian Chemist, Dimitri Mendeleev created developed the first periodic table closest to what is used today. He arranged the elements by atomic mass and predicted the discovery of excisting elements, which he left space for on his table.

Lord Rayleigh

1895

The discovery of agron was made in 1895 by Lord Rayleigh, who also found that the element dod not fit into any of the know periodic groups.

William Ramsey

1898

In 1898, William Ramsey suggested that the element argon be placed in a group named ‘zero’ due to its zero valency, along with helium. It was placed in between chlorine and potassium.

Ernest Rutherford

1911

Ernest Rutherford led to the determination of nucleaar charge by puplishing studies of the scattering of alpha particles by heavy atom nuclei, in 1911. He showed the atomic weight of an element and the nuclear charge of its nucleus were proportional.

Glenn Seaborg

1940

The last major chnage made to the periodic tale of the elements was by a man named Glenn Seaborg, in 1940. Gelnn Seaborg discovered all the transuranic elements from 94 to 102. He palced the actinide series below the lanthanide series. As a consequence of his success, Glenn Seaburg recienved the Noble Prize in 1951 and element 106 has been named in his honour ‘seaborgium’ (Sg).