I learned it today- periodic table, elements and related timeline

In the modern periodic table 118 known elements got the place out of which 94 were found naturally on earth and 24 to be created in a lab. The international union of pure and applied chemistry (IUPAC) has an inter divisional committee on Nomenclature and Symbols. This committee is recognized as world authority in developing standards for the naming of elements and compounds.

Basis of order in periodic table – Increasingly atomic number

Atomic number = proton number ( protons and electrons are equal in number )

Note – proton is not a fundamental particle but electron is. Protons are made up of quarks, another fundamental particle.

Creation of synthetic elements – Anthropological manipulation of fundamental particle in a nuclear reactor, particle accelerators or atomic explosions- 95 to 118(24 elements )

How to create synthetic ones?- Force additional proton onto the nucleus of an natural element ( atomic number lower than 95)

But!- All synthetic elements are unstable 

Note – 5 very rare natural elements were created artificially later known to be found in nature in trace quantities.

  • Technetium- 43(1937)
  • Plutonium- 94(1940) – limit of atomic numbers to exist naturally, this is so rare that it’s better to synthesise it. Usage – atomic bomb, nuclear reactors 

Why not found in earth naturally – elements above 94 got decayed into lighter elements with the age of the earth (4.6 billion years )

Why are the nuclei of some elements unstable?- Not enough strong nuclear force to hold the nucleus permanently ( strong nuclear force is one of the four fundamental forces ( strong , weak nuclear force, electromagnetic force and  gravitational force (classical) leading a radioactive nuclei.

So we got natural elements

 (1)common and stable 

(2)common and radioactive

  • Bi-83-bismuth
  • Th-90-thorium
  • U-92-uranium 

(3)rare and radioactive but produced synthetically

  • Technetium 43
  • Promethium 61
  • Astatine 85
  • Neptunium 93
  • Plutonium 94
  • Francium87

 and 

(4)the not be found naturally 24 synthetic elements (radioactive)(95-118)

  •  Americium 
  • Curium
  • Berkelium
  • Californium
  • Einsteinium 
  • Fermium
  • Mendelevium 
  • Nobelium 
  • Lawrencium 
  • Rutherfordium 
  • Dubnium 
  • Seaborgium 
  • Nielsbohrium
  • Hassium
  • Meitnerium
  • Darmstadtium
  • Roentgenium 
  • Ununbium
  • Ununtrium
  • Ununquadium
  • Ununpentium
  • Ununhexium
  • Ununoctium

Here’s the timeline of discovery and invention of elements 

9000 bce- chalcolithic age- copper(29)

3750 bce- Egyptians and  Sumerians- carbon(6),recognised as element by Antoine Lavoisier 

Ancient India , China, Greece – sulfur (16), (Lavoisier)

 1300 bc c.-Iron Age -iron (26), 

tin, lead,, mercury, silver, and gold are known to humans

Pre-a.d. 1600: arsenic, antimony, bismuth, and zinc are known to humans.

1669-Hennig Brand-  phosphorus.

1735- Georg Brandt – cobalt.

c. 1748 – Don Antonio de Ulloa – platinum .

1751    – Fredrik Cronstedt – nickel .

1766 – Henry Cavendish – hydrogen .

1772 – Daniel Rutherford – nitrogen .

1774 – Carl Wilhelm Scheele –  chlorine .

1774 –    Johann Gottlieb Gahn – manganese .

1774 – Joseph Priestley and  Carl Wilhelm Scheele – oxygen .

1781 – Peter Jacob Hjelm – molybdenum .

c. 1782 – Baron Franz Joseph Müller von Reichenstein – tellurium .

1783 – Don Fausto D’Elhuyard, Don Juan José D’Elhuyard, and  Carl Wilhelm Scheele – tungsten

1789-    Martin Klaproth – uranium.

1789-   Martin Klaproth – zirconium.

1791-    William Gregor- titanium.

1794-  Johan Gadolin – yttrium.

1797-    Louis-Nicolas Vauquelin – chromium.

1798- Louis-Nicolas Vauquelin – beryllium.

1801- Charles Hatchett – niobium.

1801- Andrés Manuel del Río – vanadium.

1802-  Anders Gustaf Ekeberg – tantalum.

1803- William Hyde Wollaston – palladium.

1803- Jöns Jakob Berzelius and Wilhelm Hisinger, and Martin Klaproth – black rock of Bastnas, Sweden, which led to the discovery of several elements

1804- William Hyde Wollaston – rhodium .

1804- Smithson Tennant – osmium .

1804-    Smithson Tennant  – iridium .

1807    English chemist Sir Humphry Davy  – potassium .

1807      Sir Humphry Davy  – sodium .

1808      Sir Humphry Davy  – barium .

1808      Sir Humphry Davy  – strontium .

1808      Sir Humphry Davy  – calcium .

1808      Sir Humphry Davy  – magnesium

1808      Louis Jacques Thênard and Joseph Louis Gay-Lussac – boron.

1811      Bernard Courtois  – iodine.

1817        Johan August Arfwedson  – lithium.

1817        Friedrich Stromeyer  – cadmium.

1818        Jöns Jakob Berzelius and J. G. Gahn – selenium.

1823        Jöns Jakob Berzelius – silicon.

1825            Hans Christian Oersted – aluminum.

1826        Antoine-Jérôme Balard – bromine.

1828        Jöns Jakob Berzelius – thorium.

1830        Nils Gabriel Sefström – vanadium.

1839        Carl Gustav Mosander – cerium

1839        Carl Gustav Mosander  – lanthanum .

1843        Carl Gustav Mosander – terbium .

1843        Carl Gustav Mosander – erbium .

1844        Carl Ernst Claus  – ruthenium .

c. 1861        Robert Bunsen and Gustav Kirchhoff – cesium .

c. 1861        Robert Bunsen and Gustav Kirchhoff – rubidium .

1861        Sir William Crookes – thallium .

1863        Ferdinand Reich and Hieronymus Theodor Richter – indium .

1875    Paul-émile Lecoq de Boisbaudran – gallium .

1878    Jean-Charles-Galissard de Marignac receives partial credit for the discovery of ytterbium .

1879        Per Teodor Cleve – holmium

1879        Per Teodor Cleve – thulium.

1879        Lars Nilson – scandium.

1879        Lars Nilson receives partial credit for the discovery of ytterbium.

1880        Paul-Émile Lecoq de Boisbaudran – samarium.

1880        Jean-Charles-Galissard de Marignac  – gadolinium.

1885        Carl Auer (Baron von Welsbach)  –  praseodymium.

1885        Carl Auer (Baron von Welsbach)  – neodymium.

1885        Clemens Alexander Winkler  – germanium.

1886        Henri Moissan  – fluorine.

1886        Paul-Émile Lecoq de Boisbaudran – dysprosium.

1894        Lord Rayleigh and William Ramsav  – argon.

1895        Sir William Ramsay and Per Teodor Cleve and Nils Abraham Langlet- helium.

1898      William Ramsay and Morris Travers   krypton.

1898        William Ramsay and Morris Travers   neon.

1898        William Ramsay and Morris Travers   xenon.

1898        Marie and Pierre Curie  – polonium.

1898        Marie and Pierre Curie  – radium.

1899        André Debierne  – actinium.

1900        Friedrich Ernst Dorn  – radon.

1901        Eugène-Anatole Demarçay  – europium.

1907        Georges Urbain  – lutetium.

1907        Georges Urbain receives partial credit for the    – ytterbium.

1917        Use Meitner and Otto Hahn  – protactinium.

1923        Dirk Coster and George Charles de Hevesy  – hafnium.

1925        Walter Noddack, Ida Tacke, and Otto Berg  – rhenium.

1933        Marguerite Perey – francium.

1939        Emilio Segré and Carlo Perrier  – technetium.

1940    Edwin M. McMillan (1907-91) and Philip H. Abelson prepare neptunium.- first transuranium element 

1940    Dale R. Corson, Kenneth R. Mackenzie, and Emilio Segré  – astatine.

1940      Glenn Seaborg and others prepare plutonium.

1944      Glenn Seaborg, Albert Ghiorso, Ralph A. James, and Leon O. Morgan prepare americium

1944    Glenn Seaborg, Albert Ghiorso, and Ralph A. James prepare curium .

1945      Oak Ridge Laboratory  – promethium .

1949    University of California at Berkeley -berkelium .

1950      Glenn Seaborg, Albert Ghiorso, Kenneth Street, Jr., and Stanley G. Thompson prepare californium .

1954    University of California at Berkeley researchers  – einsteinium .

1954    Albert Ghiorso and others – fermium .

4 new elements -2000s

Japan – Nihonium-nh -113

Moscow – Moscovium-mc -115

Russia – Oganesson- og -118

2010-Tennessee -Tennessine- Ts – 117 – oak ridge national lab

Future of elements- 

 Though there are 118 places further experiments and research are still going on for example Russian and German researchers tried to synthesise UNBINILIUM ( hypothetical 120th element)by bombarding plutonium with Iron and uranium with nickel. Maybe in future advanced technologies will lead to more discoveries. Nobel laureate Richard Feynman predicted 137 to be the limit based on Einstein’s theory of relativity. Larger the atomic nuclei = faster the speed, but speed of light is the limit . With the same logic some claim this limit to be around 170 elements.

IUPAC requirements related to time for considering as element – must exist with minimum lifetime of 10^-14 seconds 

Examples of hypothetical elements 

UNUNENNIUM-119

UNBINILIUM- 120

UNBIUNIUM-121

UNBIBIUM-122

UNBIQUADIUM-124

UNBIHEXIUM – 126 

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