History of the Periodic Table

Events

Finding of Phosphorus

Approx. 1669

A German merchant and amateur Hennig Brand attempted to create a stone which can turn anything to gold. So they heated Residues and liquid came out and that is how phosphorus was found

At least 47 elements have been found

1809

scientists began to see the pattern in the characteristics of these elements.

Divided into groups

Approx. 1863

English chemist, John Newlands divided the already discovered 56 elements into 11 groups, based on characteristics.

Creation of the Periodic Table

Approx. 1869

A Chemist from Russia named Dimitri Mendeleev started the development of the periodic table. He arranged the chemical elements by atomic mass. He left some space out so later discovered elements could fit in the table.

Noble gases

1894

Sir William Ramsay and Lord Rayleigh discovered the noble gases it was then added into the periodic table after a bit into a group named 0.

Electron discovered

Approx. 1897

J. J. Thomson, an English physicist first discovered electrons, John Townsend and Robert Millikan then determined their exact charge and mass.

Neutrons, and Isotopes were identified.

Approx. 1932

James Chadwick first discovered neutrons, and isotopes were identified. This was the complete basis for the periodic table.

Atomic number 92

1945

Glenn Seaborg identified lanthanides and actinides, it is also known as Atomic number 92, which is usually placed below the periodic table.