History of the Periodic table

Events

Discovery of phosphorous.

1649

The first scientific discovery of an element occurred in 1649 when Hennig Brand discovered the element Phosphorous.

Cobalt was discovered

1735

Swedish chemist Georg Brandt discovered the element Cobalt

Discovery of Nickel

1751

nickel was discovere∂ by Swedish Chemist Axel Fredrick Cronstedt.

Discovery of Hydrogen

1766

Henry Cavendish discovered Hydrogen as a colorless, odourless gas that burns and can form an explosive mixture with air

Discovery of Oxygen

1774

Joseph Priestly discovers Oxygen

Atomic theory developed

1808

English chemist, John Dalton who developed an atomic theory in 1803. Dalton 's atomic theory contains five basic assumptions: All matter consists of tiny particles called atoms.

First draft of Periodic table is Introduced

1828

Jakob Berzelius developed a table of atomic weights & introduced letters to symbolize elements

3 Groups of elements

1828

Johann Dobereiner developed groups of 3 elements with similar properties

Modern Periodic table intoduced

1869

The modern edition of the periodic table was first published outside Russia by Dmitri Mendeleev.

Radio activity discovered

1890 - 1900

Marie and Pierre Curie worked with uranium ore, extracting the uranium from it and experimenting with it and studying it. As a result, they discovered and were able to isolate radioactive materials.

Noble Gasses are Discovered

1894

William Ramsay discovered the Noble Gases.

Argon is discovered

1895

Lord Rayleigh discovered Argon

Electron discovery

1897

J. J. Thompson discovered the electron in 1897

Atomic nucleus was discovered

1911

The atomic nucleus was discovered in 1911 by Ernest Rutherford made up of protons and neutrons

Electron Cloud Model

1926

Erwin Schrödinger developed an “Electron Cloud Model” in 1926. It consisted of a dense nucleus surrounded by a cloud of electrons at various levels in orbitals.

developed an Electron Cloud Model

1926

Erwin Schrödinger developed an “Electron Cloud Model” in 1926. It consisted of a dense nucleus surrounded by a cloud of electrons at various levels in orbitals.