Periodic Table

Events

Aristotle

330 BC

Aristotle proposes the four element theory: earth, air, fire and water.

Antoine Lavoisier

1778

Wrote the first extensive list of elements containing 33 elements and distinguished between metals and non-metals

John Dalton

1803

Proposed "Dalton's Law" describing the relationship between the components in a mixture of gases.

Johann Dobereiner

1828

Developed groups of 3 elements with similar properties.

Lothar Meyer

1864

Arranged the known elements in order of atomic weights and observed similarities between some elements.

Dmitri Mendeleev

1869

Produced a table based on atomic weights but arranged "periodically" with elements with similar properties under each other. His Periodic Table included the 66 known elements organised by atomic weights.

Henry Moseley

1913

Determined the atomic number of each of the elements and modified the "Periodic Law"

Glenn Seaborg

1940

Synthesised transuranic elements (the elements after uranium in the eriodic table)