-
330
The Four Element Theory [330 BC]
Aristotle proposed the four element theory which consisted of: Earth, Air, Water, and Fire. -
440
The Idea of An Atom [440 BC]
Democritus and Leucippus propose the idea of an atom which they believe is an invisible particle in which everything is made up of. -
The Scientific Method
Sir Francis Bacon published 'The proficience and advancement of learning' which contained a description of what would later be known in future as 'The Scientific Method'. -
Phosphorous is Discovered!
Hennig Brand attempted to create a Philosopher's Stone; an object which could turn metals into gold. He heated residues and a liquid dropped out and burst into flames. This was the discovery of Phosphorous. -
Joseph Black and Carbon Dioxide
Joseph Black isolated Carbon Dioxide and referred to it as 'fixed air'. -
The Isolation of Oxygen
Carl Wilhelm Scheele and Joseph Priestly isolate the element of Oxygen -
The Discovery of Hydrogen!
Henry Cavendish discovered Hydrogen and describes it as a colourless, odourless gas that burns and can form an explosive mixture with air. -
The First List of Elements
Antoine Lavoisier wrote the first list of elements which contained 33 elements and identified the metals and non-metals. -
The Dalton Law
John Dalton proposed the 'Dalton Law' which describes the relationship between the components in a mixture of the gases. -
Atomic Weights and Letter Symbols
Jakob Berzilius developed a table of atomic weights and introduced letters to symbolise different elements. -
Simple Groups of Elements
Johann Dobereiner developed groups of 3 elements with similar properties -
Arranging the Elements
John Newlands arranged the known elements in order of atomic weights and observed some similarities between different elements. -
The Discovery of the Noble Gases
William Ramsay discovered the Noble Gases. -
The Source of Radio Activity
Ernest Rutherford discovered the source of radioactivity as decaying atoms -
The Modification of the Atomic Law
Henry Moseley determined the atomic number of each of the elements and modified the 'Periodic Law'. -
Transuranic Element
Glenn Seaborg synthesised transuranic elements which are all the elements after Uranium. -
Neptunium
Edwin McMillan and Philip H. Abelson identify neptunium, the lightest and first synthesized transuranium element, found in the products of uranium fission.