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Timeline of chemical element discoveries facts for kids

Kids Encyclopedia Facts

Have you ever wondered how scientists found all the amazing building blocks of our universe? This page tells the story of how the 118 chemical elements we know about today were discovered. We'll explore them in the order they were first identified as pure substances. It's often tricky to pinpoint the exact discovery date for many elements. For each element, you'll find its name, its atomic number (which is like its unique ID), the year it was first reported, who discovered it, and interesting facts about its journey to discovery.


Exploring the Periodic Table by Discovery Time

This table shows the Periodic table with each element colored based on when it was discovered. It helps us see how our understanding of elements grew over time!

Periodic table by era of discovery
1 2   3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Group →  
↓ Period  
1 1
H		 2
He
2 3
Li		 4
Be		 5
B		 6
C		 7
N		 8
O		 9
F		 10
Ne
3 11
Na		 12
Mg		 13
Al		 14
Si		 15
P		 16
S		 17
Cl		 18
Ar
4 19
K		 20
Ca		 21
Sc		 22
Ti		 23
V		 24
Cr		 25
Mn		 26
Fe		 27
Co		 28
Ni		 29
Cu		 30
Zn		 31
Ga		 32
Ge		 33
As		 34
Se		 35
Br		 36
Kr
5 37
Rb		 38
Sr		 39
Y		 40
Zr		 41
Nb		 42
Mo		 43
Tc		 44
Ru		 45
Rh		 46
Pd		 47
Ag		 48
Cd		 49
In		 50
Sn		 51
Sb		 52
Te		 53
I		 54
Xe
6 55
Cs		 56
Ba		 1 asterisk 71
Lu		 72
Hf		 73
Ta		 74
W		 75
Re		 76
Os		 77
Ir		 78
Pt		 79
Au		 80
Hg		 81
Tl		 82
Pb		 83
Bi		 84
Po		 85
At		 86
Rn
7 87
Fr		 88
Ra		 1 asterisk 103
Lr		 104
Rf		 105
Db		 106
Sg		 107
Bh		 108
Hs		 109
Mt		 110
Ds		 111
Rg		 112
Cn		 113
Nh		 114
Fl		 115
Mc		 116
Lv		 117
Ts		 118
Og
 
1 asterisk 57
La		 58
Ce		 59
Pr		 60
Nd		 61
Pm		 62
Sm		 63
Eu		 64
Gd		 65
Tb		 66
Dy		 67
Ho		 68
Er		 69
Tm		 70
Yb		  
1 asterisk 89
Ac		 90
Th		 91
Pa		 92
U		 93
Np		 94
Pu		 95
Am		 96
Cm		 97
Bk		 98
Cf		 99
Es		 100
Fm		 101
Md		 102
No		  
 

A Visual Journey Through Element Discoveries

This timeline shows when different elements were discovered, from the 1600s all the way to 2026!

Oganesson Tennessine Livermorium Moscovium Flerovium Nihonium Copernicium Roentgenium Darmstadtium Meitnerium Hassium Bohrium Seaborgium Dubnium Rutherfordium Lawrencium Nobelium Mendelevium Fermium Einsteinium Californium Berkelium Curium Americium Plutonium Neptunium Uranium Protactinium Thorium Actinium Radium Francium Radon Astatine Polonium Thallium Iridium Osmium Rhenium Tungsten Tantalum Hafnium Lutetium Ytterbium Thulium Erbium Holmium Dysprosium Terbium Gadolinium Europium Samarium Promethium Neodymium Praseodymium Cerium Lanthanum Barium Cesium Xenon Iodine Tellurium Indium Cadmium Palladium Rhodium Ruthenium Technetium Molybdenum Niobium Zirconium Yttrium Strontium Rubidium Krypton Bromine Selenium Germanium Gallium Nickel Cobalt Manganese Chromium Vanadium Titanium Scandium Calcium Potassium Argon Chlorine Phosphorus Silicon Aluminum Magnesium Sodium Neon Fluorine Oxygen Nitrogen Boron Beryllium Lithium Helium Hydrogen Bismuth Arsenic Platinum Zinc Mercury (element) Sulfur Antimony Tin Iron Silver Lead Copper Carbon Gold

How Element Discoveries Grew Over Time

Cumulative diagram of element discoveries
This diagram shows how many elements were discovered over time, from 1750 to 2023. Notice how the number of discoveries grew steadily! It also shows when the Periodic Table was invented by Mendeleev in 1869.

Ancient Discoveries: Elements Known for Ages

Some elements have been known and used by humans since ancient times, long before scientists understood what elements truly were!

Z Element Earliest use Oldest
existing
sample		 Discoverer(s) Place of
oldest
sample		 Notes
79 Gold 40000 BC 4600 BC – 4200 BC Earliest humans Varna Necropolis Humans have known about gold for a very long time! Small pieces of natural gold were found in Spanish caves from around 40,000 BC. The oldest gold jewelry, from about 4600–4200 BC, was found in Bulgaria. Scientists officially recognized it as an element in 1787.
6 Carbon 26000 BC 26000 BC Earliest humans Carbon, found in charcoal and soot, was known to early humans. The oldest charcoal paintings are about 28,000 years old! Ancient Egyptians and Sumerians used charcoal to make bronze. Diamonds, another form of carbon, were known by 2500 BC. In 1772, Antoine Lavoisier showed that diamonds, graphite, and charcoal are all made of the same basic substance. It was officially listed as an element in 1787.
29 Copper 9000 BC 6000 BC Middle East Asia Minor Copper was first found as a natural metal and later extracted from rocks. People in the Middle East likely discovered it around 9000 BC. It was very important during the Stone Age and Bronze Age. Copper beads from 6000 BC were found in Turkey. The oldest evidence of melting copper from rocks dates back to 5000 BC in Serbia. Scientists recognized copper as an element in 1787.
82 Lead 7000 BC 3800 BC Asia Minor Abydos, Egypt People started melting lead from rocks about 9,000 years ago. The oldest lead object, a small statue, was found in Egypt and dates to around 3800 BC. Lead was officially recognized as an element in 1787.
47 Silver Before 5000 BC ca. 4000 BC Asia Minor Asia Minor Silver was likely discovered in Asia Minor soon after copper and gold. It was officially recognized as an element in 1787.
26 Iron Before 5000 BC 4000 BC Middle East Egypt Iron has been known since before 5000 BC. The oldest iron items are beads made from meteoric iron (from space!) in Egypt around 4000 BC. Learning to melt iron from rocks around 3000 BC led to the Iron Age (around 1200 BC), when iron was used for tools and weapons. It was recognized as an element in 1787.
50 Tin 3500 BC 2000 BC Asia Minor Kestel Tin was first melted with copper around 3500 BC to create bronze, starting the Bronze Age. An ancient tin mine in Turkey was used from 3250 to 1800 BC. The oldest tin objects are from about 2000 BC. Tin was officially recognized as an element in 1787.
51 Antimony 3000 BC 3000 BC Sumerians Middle East A very pure antimony artifact, possibly part of a vase, was found in Iraq and dates to about 3000 BC. Ancient writers described accidentally making metallic antimony. The Muslim alchemist Jabir ibn Hayyan (around 850–950 AD) described how to intentionally separate it. In Europe, it was used by 1540. Lavoisier likely recognized it as an element in 1787.
16 Sulfur Before 2000 BC Middle East Middle East Sulfur was first used over 4,000 years ago. Ancient Egyptians used sulfur ointment for eye problems. Alchemists in the 8th and 9th centuries thought it was a basic building block of metals. Paracelsus in the 16th century also called it a universal element. Antoine Lavoisier recognized sulfur as a true element in 1777, a discovery confirmed by other scientists later.
80 Mercury 1500 BC 1500 BC Egyptians Egypt The mineral cinnabar, which contains mercury, was used as a colorful paint since 9000 BC. Small amounts of mercury metal were found in Turkish mines from 8000 years ago. Mercury was also found in Egyptian tombs from 1500 BC. Medieval alchemists and later scientists in 1787 recognized it as an element.
30 Zinc Before 1000 BC 1000 BC Indian metallurgists Indian subcontinent Zinc was used in brass by Indian metalworkers before 1000 BC, though they didn't fully understand it. A 4th-century BC vase from India shows that metallic zinc was known then. Zinc was melted in China and India around 1300 AD. The alchemist Paracelsus named it in 1526. It was fully isolated and described by Andreas Sigismund Marggraf in 1746.
78 Platinum c. 600 BC – AD 200 c. 600 BC – AD 200 Pre-Columbian South Americans South America Ancient South Americans used platinum to make white gold alloys. An Egyptian pharaoh's box from around 650 BC had gold-platinum decorations. Europeans first described this metal in 1557. Antonio de Ulloa observed it in Peru in 1735. William Brownrigg first referred to it as a new metal in 1750.
33 Arsenic c. AD 300 c. AD 300 Egyptians Middle East The Egyptian alchemist Zosimos described using metallic arsenic. The Muslim alchemist Jabir ibn Hayyan (around 850–950 AD) later described how to purify it. In Europe, Johann Schröder prepared metallic arsenic in 1641. It was recognized as an element in 1787.
83 Bismuth c. 1500 c. 1500 European alchemists and Inca civilisation Europe and South America Bismuth was known in ancient times but often confused with tin and lead. The Incas used bismuth in a special bronze alloy for knives. Agricola in the 1500s said bismuth was a distinct metal. In 1753, Claude François Geoffroy proved it was different from lead and tin.

Modern Discoveries: New Elements Found by Scientists

In more recent times, scientists used new methods to discover and isolate elements. Sometimes, elements were known in compounds for a long time before their pure form was found!

Z Element Observed Isolated (widely known) Notes
Year By Year By
15 Phosphorus 1669 H. Brand 1669 H. Brand Hennig Brand prepared and isolated phosphorus from urine. It was the first element whose discovery date and discoverer are clearly recorded. Antoine Lavoisier later recognized it as an element.
1 Hydrogen 1671 R. Boyle 1671 R. Boyle Robert Boyle made hydrogen by mixing iron filings with acid. Henry Cavendish in 1766 was the first to realize it was a unique gas. Lavoisier named it in 1783.
11 Sodium 1702 G. E. Stahl 1807 H. Davy Georg Ernst Stahl suggested that sodium and potassium salts were different in 1702. Humphry Davy isolated both sodium and potassium metals in 1807 using electricity.
19 Potassium 1702 G. E. Stahl 1807 H. Davy
27 Cobalt 1735 G. Brandt 1735 G. Brandt Georg Brandt proved that the blue color in glass came from a new metal, not bismuth as people thought.
20 Calcium 1739 J. H. Pott 1808 H. Davy Lime was known for centuries, but its chemical nature was understood in the 18th century. Scientists suggested it was an element's oxide in 1787. Humphry Davy isolated the metal using electricity in 1808.
14 Silicon 1739 J. H. Pott 1823 J. Berzelius Silicon compounds like rock crystals were known to ancient people. In 1739, Johann Heinrich Pott recognized silica as a unique "earth." Lavoisier thought the element must exist. Jöns Jakob Berzelius obtained the pure element in 1823.
13 Aluminium 1746 J. H. Pott 1825 H.C.Ørsted Paracelsus recognized "alumina" as different from other substances in 1570. Lavoisier predicted in 1787 that alumina was the oxide of an undiscovered element. Hans Christian Ørsted was the first to isolate metallic aluminium in 1825.
28 Nickel 1751 F. Cronstedt 1751 F. Cronstedt Axel Fredrik Cronstedt found nickel while trying to get copper from a mineral called "fake copper."
12 Magnesium 1755 J. Black 1808 H. Davy Joseph Black noticed that "magnesia alba" (MgO) was different from lime (CaO) in 1755. Humphry Davy isolated the metal using electricity in 1808.
25 Manganese 1770 T. O. Bergman 1774 J. G. Gahn Torbern Olof Bergman identified a new metal in a mineral but couldn't get it out. Johan Gottlieb Gahn isolated it in 1774 by heating its oxide with carbon.
9 Fluorine 1771 W. Scheele 1886 H. Moissan Carl Wilhelm Scheele studied fluorspar and realized it was a salt of a new acid. Lavoisier listed a "fluorine radical" in 1789. Many tried to isolate it, and Henri Moissan finally succeeded in 1886.
8 Oxygen 1771 W. Scheele 1771 W. Scheele Carl Wilhelm Scheele made oxygen in 1771 by heating certain compounds, but published later. Joseph Priestley also made it in 1774. Antoine Lavoisier was the first to recognize it as a true element and named it in 1777.
7 Nitrogen 1772 D. Rutherford 1772 D. Rutherford Daniel Rutherford discovered nitrogen while studying air. He showed that air, even after removing carbon dioxide, couldn't support burning. Lavoisier named it in 1775–76.
56 Barium 1772 W. Scheele 1808 H. Davy Carl Wilhelm Scheele found a new "earth" (barium oxide) in a mineral in 1772. Humphry Davy isolated the metal using electricity in 1808.
17 Chlorine 1774 W. Scheele 1774 W. Scheele Carl Wilhelm Scheele obtained chlorine from hydrochloric acid but thought it was an oxide. In 1810, Humphry Davy correctly identified it as an element.
42 Molybdenum 1778 W. Scheele 1788 J. Hjelm Carl Wilhelm Scheele recognized molybdenum as a metal in a mineral. Peter Jacob Hjelm isolated it in 1788.
74 Tungsten 1781 W. Scheele 1783 J. and F. Elhuyar Carl Wilhelm Scheele showed that a mineral contained a new acid. The Elhuyar brothers then isolated the element in 1783. It is known as both tungsten and wolfram.
52 Tellurium 1782 F.-J.M. von Reichenstein 1798 H. Klaproth Franz-Joseph Müller von Reichenstein observed tellurium as an impurity in gold ores. Martin Heinrich Klaproth isolated it in 1798.
5 Boron 1787 L. Guyton de Morveau, A. Lavoisier, C. L. Berthollet, and A. de Fourcroy 1809 H. Davy Borax was known for a long time. In 1787, scientists listed a "boron radical." Humphry Davy announced the isolation of boron in 1809.
1789 A. Lavoisier Antoine Lavoisier created the first modern list of chemical elements. He also redefined what an "element" truly means.
40 Zirconium 1789 H. Klaproth 1824 J. Berzelius Martin Heinrich Klaproth identified a new oxide in zircon in 1789. Jöns Jakob Berzelius isolated the element in 1824.
92 Uranium 1789 H. Klaproth 1841 E.-M. Péligot Martin Heinrich Klaproth mistakenly identified a uranium oxide as the element itself in 1789 and named it after the planet Uranus. Eugène-Melchior Péligot isolated the pure metal in 1841.
38 Strontium 1790 A. Crawford 1808 H. Davy Adair Crawford found that a mineral called strontianite contained a new "earth" in 1790. Humphry Davy isolated strontium using electricity in 1808.
22 Titanium 1791 W. Gregor 1875 D. K. Kirillov William Gregor found an oxide of a new metal in a mineral in 1791. Martin Heinrich Klaproth independently discovered it in 1795 and named it. Pure metallic titanium was obtained in 1910.
39 Yttrium 1794 J. Gadolin 1843 H. Rose Johan Gadolin discovered a new "earth" in a mineral in 1794. Heinrich Rose correctly isolated the element in 1843.
24 Chromium 1797 N. Vauquelin 1798 N. Vauquelin Louis Nicolas Vauquelin analyzed a mineral in 1797 and then isolated the metal in 1798 by heating its oxide with charcoal.
4 Beryllium 1798 N. Vauquelin 1828 F. Wöhler and A. Bussy Louis Nicolas Vauquelin discovered beryllium oxide in beryl and emerald in 1798. Friedrich Wöhler and Antoine Bussy independently isolated the metal in 1828.
23 Vanadium 1801 A. M. del Río 1867 H. E. Roscoe Andrés Manuel del Río found this metal in 1801, but his claim was initially dismissed. Nils Gabriel Sefström rediscovered it in 1830 and named it vanadium. Henry Enfield Roscoe produced the pure metal in 1867.
41 Niobium 1801 C. Hatchett 1864 W. Blomstrand Charles Hatchett found this element in an ore and named it "columbium." Later, Heinrich Rose proved it was distinct from tantalum and renamed it niobium. Niobium was officially accepted in 1949.
73 Tantalum 1802 G. Ekeberg 1864 J.C.G. de Marignac Anders Gustaf Ekeberg found this element in minerals and named it after Tantalus because it was hard to dissolve. Jean Charles Galissard de Marignac produced relatively pure tantalum in 1864.
46 Palladium 1802 W. H. Wollaston 1802 W. H. Wollaston William Hyde Wollaston discovered palladium in platinum samples from South America. He named it after the newly discovered asteroid Pallas.
58 Cerium 1803 H. Klaproth, W. Hisinger, and J. Berzelius 1875 W. F. Hillebrand and T. H. Norton Wilhelm Hisinger and Jöns Jakob Berzelius discovered a new "earth" in a mineral and named the element after the asteroid Ceres. Martin Heinrich Klaproth also discovered it. Pure cerium was isolated in 1875.
76 Osmium 1803 S. Tennant 1803 S. Tennant Smithson Tennant discovered two new elements, osmium and iridium, in platinum samples. He published his findings in 1804.
77 Iridium 1803 S. Tennant and H.-V. Collet-Descotils 1803 S. Tennant
45 Rhodium 1804 H. Wollaston 1804 H. Wollaston William Hyde Wollaston discovered and isolated rhodium from crude platinum samples.
53 Iodine 1811 B. Courtois 1811 B. Courtois Bernard Courtois discovered iodine in the ashes of seaweed. Joseph Louis Gay-Lussac named it "iode" in French, and Humphry Davy gave it the English name "iodine."
3 Lithium 1817 A. Arfwedson 1821 W. T. Brande Johan August Arfwedson discovered this alkali metal in a mineral. William Thomas Brande isolated it using electricity in 1821.
48 Cadmium 1817 S. L Hermann, F. Stromeyer, and J.C.H. Roloff 1817 S. L Hermann, F. Stromeyer, and J.C.H. Roloff These three scientists found an unknown metal in a zinc oxide sample. The name given by Friedrich Stromeyer became the accepted one.
34 Selenium 1817 J. Berzelius and G. Gahn 1817 J. Berzelius and G. Gahn While working with lead, Jöns Jakob Berzelius and Johann Gottlieb Gahn discovered a substance they first thought was tellurium, but later realized it was a new element.
35 Bromine 1825 J. Balard and C. Löwig 1825 J. Balard and C. Löwig Both Antoine Jérôme Balard and Carl Jacob Löwig discovered bromine in the autumn of 1825. Balard published his findings first.
90 Thorium 1829 J. Berzelius 1914 D. Lely, Jr. and L. Hamburger Jöns Jakob Berzelius obtained a new "earth" (the oxide of a new element) from a mineral in 1829.
57 Lanthanum 1838 G. Mosander 1904 W. Muthmann, L. Weiss Carl Gustaf Mosander found a new "earth" in ceria samples in 1838.
60 Neodymium 1841 G. Mosander 1901 W. Muthmann, H. Hofer, L. Weiss Carl Gustaf Mosander discovered this element and called it didymium. Later, Carl Auer von Welsbach split didymium into two elements: praseodymium and neodymium.
68 Erbium 1843 G. Mosander 1934 W. Klemm and H. Bommer Carl Gustaf Mosander separated "yttria" into yttria, erbia, and terbia. The names were later swapped due to further research, with erbia becoming the rose-colored earth and terbia the yellow earth.
65 Terbium 1843 G. Mosander 1937 W. Klemm and H. Bommer
44 Ruthenium 1844 K. Claus 1844 K. Claus Gottfried Wilhelm Osann thought he found new metals in Russian platinum in 1826, including ruthenium. In 1844, Karl Ernst Claus confirmed one new metal and reused Osann's name "ruthenium."
55 Caesium 1860 G. R. Kirchhoff and R. Bunsen 1882 C. Setterberg Gustav Kirchhoff and Robert Bunsen discovered caesium using spectrum analysis, noticing its two blue light lines. The pure metal was isolated in 1882 by Carl Setterberg.
37 Rubidium 1861 G. R. Kirchhoff and R. Bunsen 1863 R. Bunsen Gustav Kirchhoff and Robert Bunsen discovered rubidium shortly after caesium, by observing new spectral lines in a mineral. Robert Bunsen isolated the metal around 1863.
81 Thallium 1861 W. Crookes 1862 C.-A. Lamy William Crookes found a new green line in a selenium sample. Later that year, Claude-Auguste Lamy found the element to be metallic.
49 Indium 1863 F. Reich and T. Richter 1864 T. Richter Ferdinand Reich and Hieronymous Theodor Richter identified indium by its bright indigo-blue light emission. Richter isolated the metal the next year.
2 Helium 1868 N. Lockyer 1895 W. Ramsay, T. Cleve, and N. Langlet Pierre Janssen and Joseph Norman Lockyer independently observed a yellow line in the Sun's spectrum that didn't match any known element. Lockyer correctly concluded it was a new element. Years later, it was found on Earth by Sir William Ramsay, Per Theodor Cleve, and Nils Langlet.
1869 D. I. Mendeleev Dmitri Mendeleev organized the 63 known elements into the first modern periodic table. He also correctly predicted several new elements.
31 Gallium 1875 P. E. L. de Boisbaudran 1878 P. E. L. de Boisbaudran and E. Jungfleisch Paul Emile Lecoq de Boisbaudran observed light lines matching an element predicted by Mendeleev. He and Emil Jungfleisch isolated the metal three years later.
70 Ytterbium 1878 J.C.G. de Marignac 1936 W. Klemm and H. Bommer In 1878, Jean Charles Galissard de Marignac reported splitting "erbia" into two new "earths," one of which was ytterbia.
67 Holmium 1878 J.-L. Soret and M. Delafontaine 1939 H. Bommer Jacques-Louis Soret found holmium in a mineral. Later, Per Teodor Cleve separated Marignac's erbia into erbia, thulium, and holmium.
21 Scandium 1879 F. Nilson 1937 W. Fischer, K. Brünger, H. Grieneisen Lars Fredrik Nilson split ytterbia into pure ytterbia and a new element that matched Mendeleev's predicted "eka-boron."
69 Thulium 1879 T. Cleve 1936 W. Klemm and H. Bommer Per Teodor Cleve separated Marignac's erbia into erbia, thulium, and holmium.
62 Samarium 1879 P.E.L. de Boisbaudran 1903 W. Muthmann Paul Emile Lecoq de Boisbaudran noted a new "earth" in a mineral and named it samaria.
64 Gadolinium 1880 J. C. G. de Marignac 1935 Félix Trombe Jean Charles Galissard de Marignac first observed this new "earth." Later, Paul Emile Lecoq de Boisbaudran obtained a pure sample.
59 Praseodymium 1885 C. A. von Welsbach 1904 W. Muthmann, L. Weiss Carl Auer von Welsbach discovered praseodymium in Mosander's didymia.
32 Germanium 1886 C. A. Winkler 1886 C. A. Winkler In 1886, Clemens Winkler found germanium, which matched Mendeleev's predicted "eka-silicon."
66 Dysprosium 1886 P.E.L. de Boisbaudran 1937 W. Klemm and H. Bommer Paul Emile Lecoq de Boisbaudran found a new "earth" in erbia.
18 Argon 1894 Lord Rayleigh and W. Ramsay 1894 Lord Rayleigh and W. Ramsay Lord Rayleigh and William Ramsay discovered argon by comparing the weights of nitrogen from air and nitrogen made chemically. It was the first noble gas found.
63 Europium 1896 E.-A. Demarçay 1937 W. Klemm and H. Bommer Eugène-Anatole Demarçay found spectral lines of a new element in samarium and named it europium in 1901. Metallic europium was isolated in 1937.
36 Krypton 1898 W. Ramsay and W. Travers 1898 W. Ramsay and W. Travers In 1898, William Ramsay and Morris W. Travers separated krypton, a noble gas, from liquid argon.
10 Neon 1898 W. Ramsay and W. Travers 1898 W. Ramsay and W. Travers In June 1898, William Ramsay and Morris W. Travers separated neon, another noble gas, from liquid argon.
54 Xenon 1898 W. Ramsay and W. Travers 1898 W. Ramsay and W. Travers After neon, William Ramsay and Morris W. Travers separated a third noble gas, xenon, from liquid argon.
84 Polonium 1898 P. and M. Curie 1946 W. H. Beamer and C. R. Maxwell In 1898, Pierre Curie and Marie Curie noticed increased radioactivity in uranium from pitchblende, which they linked to an unknown element. They named it polonium. Pure polonium was obtained in 1946.
88 Radium 1898 P. and M. Curie 1910 Marie Curie and André-Louis Debierne The Curies reported a new element, radium, in December 1898. Marie Curie later isolated it from uraninite. In 1910, she and André-Louis Debierne isolated pure radium metal.
86 Radon 1899 E. Rutherford and R. B. Owens 1910 W. Ramsay and R. Whytlaw-Gray Ernest Rutherford and Robert B. Owens discovered a radioactive gas from thorium decay. It was later isolated by William Ramsay and Robert Whytlaw-Gray.
89 Actinium 1902 F. O. Giesel 1955 Joseph G. Stites, Murrell L. Salutsky, Bob D. Stone Friedrich Oskar Giesel obtained a substance from pitchblende similar to lanthanum. André-Louis Debierne had previously reported a new element, actinium. Both had samples containing element 89, and Debierne is generally credited.
71 Lutetium 1906 C. A. von Welsbach and G. Urbain 1937 W. Klemm and H. Bommer Carl Auer von Welsbach and Georges Urbain independently proved that ytterbium contained a new element. Urbain named it lutetium, which was adopted by the International Committee of Atomic Weights.
75 Rhenium 1908 M. Ogawa 1908 M. Ogawa Masataka Ogawa found rhenium in a mineral in 1908, but mistakenly identified it. In 1925, Walter Noddack, Ida Tacke, and Otto Berg correctly identified it as element 75 and named it rhenium.
91 Protactinium 1913 K. Fajans and O. H. Göhring 1934 A. von Grosse Kasimir Fajans and Oswald Helmuth Göhring obtained the first isotope of this element in 1913. A longer-lived isotope was found in 1918 by Otto Hahn and Lise Meitner, who named it protactinium.
72 Hafnium 1922 D. Coster and G. von Hevesy 1924 Anton Eduard van Arkel and Jan Hendrik de Boer Dirk Coster and Georg von Hevesy found hafnium using X-ray analysis in zircon. Anton Eduard van Arkel and Jan Hendrik de Boer first prepared metallic hafnium in 1924. It was the last stable element discovered.
43 Technetium 1937 C. Perrier and E. Segrè 1947 S. Fried Carlo Perrier and Emilio Segrè discovered technetium in a molybdenum sample used in a cyclotron. It was the first element discovered by making it in a lab. Small traces were later found on Earth in 1962.
87 Francium 1939 M. Perey Marguerite Perey discovered francium as a decay product of actinium. It was the last element found in nature, rather than created in a lab.
93 Neptunium 1940 E.M. McMillan and H. Abelson 1945 S. Fried Edwin McMillan and Philip H. Abelson created neptunium by shining neutrons on uranium. It was the first element heavier than uranium to be discovered. Natural traces were found in pitchblende in 1952.
85 Astatine 1940 D. R. Corson, K. R. MacKenzie and E. Segrè Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè made astatine by hitting bismuth with alpha particles. In 1943, Berta Karlik and Traude Bernert found it in nature.
94 Plutonium 1941 Glenn T. Seaborg, Arthur C. Wahl, W. Kennedy and E.M. McMillan 1943 H. L. Baumbach, S. Fried, P. L. Kirk and, R. S. Rosenfels Plutonium was made by bombarding uranium with deuterons. Glenn T. Seaborg and Morris L. Perlman later found traces of it in natural pitchblende. The first sample of plutonium metal was created in 1943.
96 Curium 1944 Glenn T. Seaborg, Ralph A. James and Albert Ghiorso 1950 J. C. Wallmann, W. W. T. Crane and B. B. Cunningham Curium was created by bombarding plutonium with alpha particles during the Manhattan Project. Curium metal was produced in 1950.
95 Americium 1944 G. T. Seaborg, R. A. James, O. Morgan and A. Ghiorso 1951 Edgar F. Westrum Jr. and LeRoy Eyring Americium was created by shining neutrons on plutonium during the Manhattan Project. Americium metal was produced in 1951.
61 Promethium 1945 Jacob A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell 1963 F. Weigel Promethium was isolated during the Manhattan Project in 1945. The metal was later isolated in 1963. It is the most recent element to have been found in trace amounts on Earth.
97 Berkelium 1949 G. Thompson, A. Ghiorso and G. T. Seaborg (University of California, Berkeley) 1969 J. R. Peterson, J. A. Fahey, and R. D. Baybarz Berkelium was created by bombarding americium with alpha particles.
98 Californium 1950 S. G. Thompson, K. Street, Jr., A. Ghiorso and G. T. Seaborg (University of California, Berkeley) 1974 R. G. Haire and R. D. Baybarz Californium was made by bombarding curium with alpha particles. Californium metal was produced in 1974.
99 Einsteinium 1952 A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) 1979 R. G. Haire and R. D. Baybarz Einsteinium was formed in the first thermonuclear explosion in November 1952. It was kept secret for several years. Einsteinium metal was produced in 1979.
100 Fermium 1953 A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) Fermium was also formed in the first thermonuclear explosion in November 1952. It was identified in early 1953 but kept secret for some years.
101 Mendelevium 1955 A. Ghiorso, G. Harvey, G. R. Choppin, S. G. Thompson and G. T. Seaborg (Berkeley Radiation Laboratory) Mendelevium was created by bombarding einsteinium with alpha particles.
103 Lawrencium 1961 A. Ghiorso, T. Sikkeland, E. Larsh and M. Latimer (Berkeley Radiation Laboratory) Lawrencium was first made by bombarding californium with boron atoms.
102 Nobelium 1965 E. D. Donets, V. A. Shchegolev and V. A. Ermakov (JINR in Dubna) Nobelium was first made by bombarding uranium with neon atoms. The first clear report of its detection came in 1966.
104 Rutherfordium 1969 A. Ghiorso et al. (Berkeley Radiation Laboratory) and I. Zvara et al. (JINR in Dubna) Rutherfordium was created by bombarding californium with carbon atoms by Albert Ghiorso's team, and by bombarding plutonium with neon atoms by I. Zvara's team.
105 Dubnium 1970 A. Ghiorso et al. (Berkeley Radiation Laboratory) and V. A. Druin et al. (JINR in Dubna) Dubnium was created by bombarding californium with nitrogen atoms by Ghiorso's team, and by bombarding americium with neon atoms by V. A. Druin's team.
106 Seaborgium 1974 A. Ghiorso et al. (Berkeley Radiation Laboratory) Seaborgium was created by bombarding californium with oxygen atoms.
107 Bohrium 1981 G.Münzenberg et al. (GSI in Darmstadt) Bohrium was made by bombarding bismuth with chromium.
109 Meitnerium 1982 G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) Meitnerium was created by bombarding bismuth with iron atoms.
108 Hassium 1984 G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) Hassium was created by bombarding lead with iron atoms.
110 Darmstadtium 1994 S. Hofmann et al. (GSI in Darmstadt) Darmstadtium was created by bombarding lead with nickel.
111 Roentgenium 1994 S. Hofmann et al. (GSI in Darmstadt) Roentgenium was created by bombarding bismuth with nickel.
112 Copernicium 1996 S. Hofmann et al. (GSI in Darmstadt) Copernicium was created by bombarding lead with zinc.
114 Flerovium 1999 Y. Oganessian et al. (JINR in Dubna) Flerovium was created by bombarding plutonium with calcium.
116 Livermorium 2000 Y. Oganessian et al. (JINR in Dubna) Livermorium was created by bombarding curium with calcium.
118 Oganesson 2002 Y. Oganessian et al. (JINR in Dubna) Oganesson was created by bombarding californium with calcium.
115 Moscovium 2003 Y. Oganessian et al. (JINR in Dubna) Moscovium was created by bombarding americium with calcium.
113 Nihonium 2003–2004 Y. Oganessian et al. (JINR in Dubna) and K. Morita et al. (RIKEN in Wako, Japan) Nihonium was created by the decay of moscovium by Oganessian's team, and by bombarding bismuth with zinc by Morita's team. Both teams published their findings in 2004.
117 Tennessine 2009 Y. Oganessian et al. (JINR in Dubna) Tennessine was created by bombarding berkelium with calcium.

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