History Of Periodic Table

Events

Phosphorous Is Discovered

1649

The first scientific discovery of an element, phosphorous. Discovered by Hannig Brand, a German scientist, through the treatment of urine. Although technically this wasn't the first element discovered, as gold and copper have being used thousands of years before hand, this was the first to be discovered through scientific means and be recorded in an early table which was the great grandfather of the modern.

The 'Telluric Screw'

1862

Alexandre-Emile Béguyer de Chancourtois, a French geologist, listed elements on a roll of paper tape, then wrapping it downward around a cylindar. This model was the first model of a periodic table, and was known as the 'telluric screw'.

Law Of Octaves

1864

John Newlands, a British, composed the idea that if the elements were organised by atomic weight, then there was a similarity every 8 elements. This was the 'law of octaves' theory.

The Birth Of The Modern Periodic Table

1869

Dmitri Mendeleev, a Russian chemist formed the familiar layout of the modern periodic table. Elements with similar properties were placed below one another, and they were ordered by atomic weight. In the table, gaps were made for elements yet to be discovered.

Noble Gases Are Discovered

1894

A Scottish chemist by the name of William Ramsey discovered a new group of elements known as noble gases. He realised that these elements needed a new group on the periodic table, and so these elements got their own column at the end.

The Atomic Numbers Are Found

1914

Henry Moseley (English) discovers the atomic number for each element. From this discovery, he said that ordering the elements on the table by atomic number was more logical and would fit better. From this, the table was changed and ordered via atomic numbers in increasing order.

Actinides

1940

Glenn Seaborg, an American chemist, produced heavy massed elements, such as neptunium. As these were different to other elements, a new group was put at the bottom of the table for these elements called 'Actinides'.