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Phosphorus was discovered by German alchemist Hennig Brand.
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Cobalt was discovered by a Swedish chemist Georg Brandt.
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Platinum was discribed by Julius Caesar Scaliger in 1557. Although the metal was observed by Antonio de Ulloa and Don Jorge Juan y Santacilia in 1748.
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Nickel was discovered by the Swedish chemist Axel Fredrik Cronstedt.
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Hydrogen was discovered by English chemist and physicist Henry Cavendish.
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Nitrogen was discovered by Scottish chemist Daniel Rutherford.
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Chlorine was discovered by a Swedish scientist, Carl Willam Scheele.
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Oxygen was discovered by English chemist Joseph Priestley and Swedish chemist Carl Wilhelm Scheele.
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Antoine Lavoisier wrote the first extensive list of elements containing 33 elements & distinguished between metals and non-metals
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Zirconium was discovered by German chemist Martin Heinrich Klaproth.
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Titanium was first discovered by English clergyman William Gregor.
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Beryllium was discovered by French chemist Louis-Nicolas Vauquelin.
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Irdium was discovered by English chemist Smithson Tennant.
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John Dalton proposed "Dalton's Law" describing the relationship between the components in a mixture of gases
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Potassium was discovered by English chemist Sir Humphry Davy.
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Sodium was discovered by English chemist Sir Humphry Davy.
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Magnesium was discovered by Joseph Black, in England, in 1755. The element was isolated by A. A. B. Bussy and Sir Humphrey Davy in 1808.
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Calcium was discovered by English chemist Sir Humphry Davy.
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Lithium was discovered by Swedish chemist Johan August Arfwedson.
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Lothar Meyer published his version of the periodic table (after Mendeleev).
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Aluminium was discovered by Danish chemist and physicist Hans Christian Oersted.
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Johann Dobereiner developed groups of 3 elements with similar properties
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Johann Dobereiner discovered the halogen triad and the alkali metal triad.
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Ruthenium was discovered by the Russian scientist Karl Ernst Claus.
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The first periodic table was created by de Chancourtois. He assembled the table by classifying chemical elements in an order based on their periodicity of chemical and physical properties.
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In 1862, French geologist Alexandre-Emile Béguyer de Chancourtois listed the elements on paper tape and wound them, spiral like, around a cylinder. Certain ‘threes’ of elements with similar properties came together down the cylinder. He called his model the ‘telluric screw’.
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In 1864, English chemist John Newlands noticed that, if the elements were arranged in order of atomic weight, there was a periodic similarity every 8 elements. He proposed his ‘law of octaves’ on this.
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In 1869, Lothar Meyer complied a periodic table of 56 elements based on a regular repeating pattern of physical properties such as molar volume. Once again, the elements were arranged in order of increasing atomic weights.
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Dmitri Mendeleev published his periodic table, eventually becoming the “father of the periodic table.”
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Russian chemist Dmitri Mendeleev produced a periodic table based on atomic weights but arranged ‘periodically’. Elements with similar properties appeared under each other. Gaps were left for yet to be discovered elements.
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Holmium was discovered by Marc Delafontaine and Jacques-Louis Soret in 1878 in Switzerland. Later in 1878, a Swedish chemist, Per Teodor Cleve independently discovered the element holmium.
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In 1894, William Ramsay discovered the noble gases and realised that they represented a new group in the periodic table.
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Helium
French astronomer Pierre Janssen in 1868 found proof that a new element helium existed in the Sun. Helium was isolated by Sir William Ramsay and independently by N. A. Langley and P. T. Cleve at 1895 in London, England and Uppsala, Sweden. -
Neon was discovered by Sir William Ramsay, a Scottish chemist, and Morris M. Travers, an English chemist.
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William Ramsey helped to establish the “zero” group (for “zero valency”) and predicted the future discovery of the element neon.
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Lutetium was independently discovered by French scientist Georges Urbain, Austrian mineralogist Baron Carl Auer von Welsbach, and American chemist Charles James
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A. van den Broek established that the atomic weight of an element was approximatelyequal to the charge on an atom. This charge became the “atomic number” by whichperiodic table elements are classified.
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Ernest Rutherford established that “the nuclear charge on a nucleus was proportional to the atomic weight of the element.”
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Henry Moseley discovered the isotopes of elements. This discovery established that
“the properties of the elements varied periodically with atomic number,” not atomic
weight, which had been previously accepted under periodic law. -
In 1914, Henry Moseley determined the atomic number of each of the known elements. He realised that, if the elements were arranged in order of increasing atomic number rather than atomic weight, they gave a better fit within the ‘periodic table’.
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Protactinium was discovered in 1917/18 by Otto Hahn and Lise Meitner.
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In 1940, Glenn Seaborg artificially produced heavy mass elements such as neptunium. These new elements were part of a new block of the periodic table called ‘actinides
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Neptunium was discovered by Edwin M. McMillan and Philip H. Abelson.
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Glenn Seaborg discovered plutonium and the transuranic elements from 94 to 102.
His findings represented the last (and most recent) changes to the periodic table. -
Promethium
Promethium was first produced at Oak Ridge National Laboratory in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell. But its discovery was announced in 1947. -
Carl Wilhelm Scheele and Joseph Priestly independently isolated oxygen
