X
H 1

Hydrogen

Greek elements hydro- and -gen, meaning 'water-forming'

Observed or predicted by H. Cavendish in 1766. Isolated by Paracelsus in 1500.

Cavendish was the first to distinguish H2 from other gases, although Paracelsus around 1500, Robert Boyle, and Joseph Priestley had observed its production by reacting strong acids with metals. Lavoisier named it in 1783. It was the first elemental gas known.

General Information

Mass1.007975Amu
Meltingpoint14.01K
Boilingpoint20.28K
Electronegativity2.2
Abundance (in earth)1400.0mg/kg
Specific Heat14.304J/(g·K)
First Ionization Energy13.5984eV
Radius1.54
Density8.988e-05g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel2S1/2
Electron Configuration1s

Isotopes

NeutronsMassAbundanceRadioactive
11.0078250322399.9885No
22.014101778120.0115No
33.01604927790No
X
He 2

Helium

Greek hḗlios, 'sun'

Observed or predicted by P. Janssen and N. Lockyer in 1868. Isolated by W. Ramsay, T. Cleve, and N. Langlet in 1895.

Janssen and Lockyer observed independently a yellow line in the solar spectrum that did not match any other element. This was the first observation of a noble gas, located in the Sun. Years later after the isolation of argon on Earth, Ramsay, Cleve, and Langlet observed independently helium trapped in cleveite.

General Information

Mass4.002602Amu
Meltingpoint-K
Boilingpoint4.22K
Electronegativity-
Abundance (in earth)0.008mg/kg
Specific Heat5.193J/(g·K)
First Ionization Energy24.5874eV
Radius1.34
Density0.0001785g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration1s2

Isotopes

NeutronsMassAbundanceRadioactive
33.01602932010.000134No
44.0026032541399.999866No
X
Li 3

Lithium

Greek líthos, 'stone'

Observed or predicted by A. Arfwedson in 1817. Isolated by W. T. Brande in 1821.

Arfwedson discovered the alkali in petalite.

General Information

Mass6.967499999999999Amu
Meltingpoint453.69K
Boilingpoint1560.0K
Electronegativity0.98
Abundance (in earth)20.0mg/kg
Specific Heat3.582J/(g·K)
First Ionization Energy5.3917eV
Radius2.2
Density0.534g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration1s2 2s

Isotopes

NeutronsMassAbundanceRadioactive
66.01512288747.59No
77.01600343792.41No
X
Be 4

Beryllium

Beryl, a mineral (ultimately from the name of Belur in southern India)

Observed or predicted by N. Vauquelin in 1798. Isolated by F. Wöhler and A. Bussy in 1828.

Vauquelin discovered the oxide in beryl and emerald, and Klaproth suggested the present name around 1808.

General Information

Mass9.0121831Amu
Meltingpoint1560.0K
Boilingpoint2742.0K
Electronegativity1.57
Abundance (in earth)2.8mg/kg
Specific Heat1.825J/(g·K)
First Ionization Energy9.3227eV
Radius2.19
Density1.85g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration1s2 2s2

Isotopes

NeutronsMassAbundanceRadioactive
99.01218307100.0No
X
B 5

Boron

Borax, a mineral (from Arabic bawraq)

Observed or predicted by L. Gay-Lussac and L.J. Thénard in 1808. Isolated by H. Davy in 1808.

Radical boracique appears on the list of elements in Lavoisier's Traité Élémentaire de Chimie from 1789. On June 21, 1808, Lussac and Thénard announced a new element in sedative salt, Davy announced the isolation of a new substance from boracic acid on June 30.

General Information

Mass10.8135Amu
Meltingpoint2349.0K
Boilingpoint4200.0K
Electronegativity2.04
Abundance (in earth)10.0mg/kg
Specific Heat1.026J/(g·K)
First Ionization Energy8.298eV
Radius2.05
Density2.34g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel2Po1/2
Electron Configuration1s2 2s2 2p

Isotopes

NeutronsMassAbundanceRadioactive
1010.012936919.9No
1111.009305480.1No
X
C 6

Carbon

Latin carbo, 'coal'

Earliest use 3750 BC. Discovered by Egyptians and Sumerians. Oldest sample from Middle East in 2500 BC.

The earliest known use of charcoal was for the reduction of copper, zinc, and tin ores in the manufacture of bronze, by the Egyptians and Sumerians. Diamonds were probably known as early as 2500 BC. True chemical analyses were made in the 18th century, and in 1789 carbon was listed by Antoine Lavoisier as an element.

General Information

Mass12.0106Amu
Meltingpoint3800.0K
Boilingpoint4300.0K
Electronegativity2.55
Abundance (in earth)200.0mg/kg
Specific Heat0.709J/(g·K)
First Ionization Energy11.2603eV
Radius1.9
Density2.267g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel3P0
Electron Configuration1s2 2s2 2p2

Isotopes

NeutronsMassAbundanceRadioactive
1212.098.93No
1313.003354835071.07No
1111.01143360No
1414.0032419880No
X
N 7

Nitrogen

Greek nítron and -gen, meaning 'niter-forming'

Observed or predicted by D. Rutherford in 1772. Isolated by D. Rutherford in 1772.

He discovered nitrogen while he was studying at the University of Edinburgh. He showed that the air in which animals had breathed, even after removal of the exhaled carbon dioxide, was no longer able to burn a candle. Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley also studied the element at about the same time, and Lavoisier named it in 1775-6.

General Information

Mass14.006855Amu
Meltingpoint63.15K
Boilingpoint77.36K
Electronegativity3.04
Abundance (in earth)19.0mg/kg
Specific Heat1.04J/(g·K)
First Ionization Energy14.5341eV
Radius1.79
Density0.0012506g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel4So3/2
Electron Configuration1s2 2s2 2p3

Isotopes

NeutronsMassAbundanceRadioactive
1414.0030740044399.636No
1515.00010889890.364No
X
O 8

Oxygen

Greek oxy- and -gen, meaning 'acid-forming'

Observed or predicted by W. Scheele in 1771. Isolated by Sendivogius in 1604.

Obtained it by heating mercuric oxide and nitrates in 1771, but did not publish his findings until 1777. Joseph Priestley also prepared this new air by 1774, but only Lavoisier recognized it as a true element; he named it in 1777. Before him, Sendivogius had produced oxygen by heating saltpetre, correctly identifying it as the 'food of life'.

General Information

Mass15.9994Amu
Meltingpoint54.36K
Boilingpoint90.2K
Electronegativity3.44
Abundance (in earth)461000.0mg/kg
Specific Heat0.918J/(g·K)
First Ionization Energy13.6181eV
Radius1.71
Density0.001429g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel3P2
Electron Configuration1s2 2s2 2p4

Isotopes

NeutronsMassAbundanceRadioactive
1615.9949146195799.757No
1716.99913175650.038No
1817.99915961290.205No
X
F 9

Fluorine

Latin fluere, 'to flow'

Observed or predicted by A.-M. Ampère in 1810. Isolated by H. Moissan in 1886.

Radical fluorique appears on the list of elements in Lavoisier's Traité Élémentaire de Chimie from 1789, but radical muriatique also appears instead of chlorine. André-Marie Ampère predicted an element analogous to chlorine obtainable from hydrofluoric acid, and between 1812 and 1886 many researchers tried to obtain this element. It was eventually isolated by Moissan.

General Information

Mass18.998403163Amu
Meltingpoint53.53K
Boilingpoint85.03K
Electronegativity3.98
Abundance (in earth)585.0mg/kg
Specific Heat0.824J/(g·K)
First Ionization Energy17.4228eV
Radius1.63
Density0.001696g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel2Po3/2
Electron Configuration1s2 2s2 2p5

Isotopes

NeutronsMassAbundanceRadioactive
1918.9984031627100.0No
1818.00093730No
X
Ne 10

Neon

Greek néon, 'new'

Observed or predicted by W. Ramsay and W. Travers in 1898. Isolated by W. Ramsay and W. Travers in 1898.

In June 1898 Ramsay separated a new noble gas from liquid argon by difference in boiling point.

General Information

Mass20.1797Amu
Meltingpoint24.56K
Boilingpoint27.07K
Electronegativity-
Abundance (in earth)0.005mg/kg
Specific Heat1.03J/(g·K)
First Ionization Energy21.5645eV
Radius1.56
Density0.0008999g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration1s2 2s2 2p6

Isotopes

NeutronsMassAbundanceRadioactive
2019.992440176290.48No
2120.993846690.27No
2221.9913851149.25No
X
Na 11

Sodium

English soda (the symbol Na is derived from New Latin natrium, coined from German Natron, 'natron')

Observed or predicted by H. Davy in 1807. Isolated by H. Davy in 1807.

Andreas Sigismund Marggraf recognised the difference between soda ash and potash in 1758. Davy discovered sodium a few days after potassium, by using electrolysis on sodium hydroxide.

General Information

Mass22.98976928Amu
Meltingpoint370.87K
Boilingpoint1156.0K
Electronegativity0.93
Abundance (in earth)23600.0mg/kg
Specific Heat1.228J/(g·K)
First Ionization Energy5.1391eV
Radius2.25
Density0.971g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration[Ne] 3s

Isotopes

NeutronsMassAbundanceRadioactive
2322.989769282100.0No
2221.994437410No
2423.990962950No
X
Mg 12

Magnesium

Magnesia, a district of Eastern Thessaly in Greece

Observed or predicted by J. Black in 1755. Isolated by H. Davy in 1808.

Black observed that magnesia alba (MgO) was not quicklime (CaO). Davy isolated the metal electrochemically from magnesia.

General Information

Mass24.3055Amu
Meltingpoint923.0K
Boilingpoint1363.0K
Electronegativity1.31
Abundance (in earth)23300.0mg/kg
Specific Heat1.023J/(g·K)
First Ionization Energy7.6462eV
Radius2.4
Density1.738g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration[Ne] 3s2

Isotopes

NeutronsMassAbundanceRadioactive
2423.98504169778.99No
2524.9858369810.0No
2625.9825929711.01No
X
Al 13

Aluminium

Alumina, from Latin alumen (gen. aluminis), 'bitter salt, alum'

Observed or predicted by H.C.Ørsted in 1825. Isolated by H.C.Ørsted in 1825.

Antoine Lavoisier predicted in 1787 that alumina is the oxide of an undiscovered element, and in 1808 Humphry Davy tried to decompose it. Although he failed, he suggested the present name. Hans Christian Ørsted was the first to isolate metallic aluminium in 1825.

General Information

Mass26.9815384Amu
Meltingpoint933.47K
Boilingpoint2792.0K
Electronegativity1.61
Abundance (in earth)82300.0mg/kg
Specific Heat0.897J/(g·K)
First Ionization Energy5.9858eV
Radius2.39
Density2.698g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel2Po1/2
Electron Configuration[Ne] 3s2 3p

Isotopes

NeutronsMassAbundanceRadioactive
2726.98153853100.0No
X
Si 14

Silicon

Latin silex, 'flint' (originally silicium)

Observed or predicted by J. Berzelius in 1823. Isolated by J. Berzelius in 1823.

Humphry Davy thought in 1800 that silica was a compound, not an element, and in 1808 suggested the present name. In 1811 Louis-Joseph Gay-Lussac and Louis-Jacques Thénard probably prepared impure silicon, but Berzelius is credited with the discovery for obtaining the pure element in 1823.

General Information

Mass28.085Amu
Meltingpoint1687.0K
Boilingpoint3538.0K
Electronegativity1.9
Abundance (in earth)282000.0mg/kg
Specific Heat0.705J/(g·K)
First Ionization Energy8.1517eV
Radius2.32
Density2.3296g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel3P0
Electron Configuration[Ne] 3s2 3p2

Isotopes

NeutronsMassAbundanceRadioactive
2827.976926534692.223No
2928.97649466494.685No
3029.9737701363.092No
X
P 15

Phosphorus

Greek phōsphóros, 'light-bearing'

Observed or predicted by H. Brand in 1669. Isolated by H. Brand in 1669.

Prepared from urine, it was the first element to be discovered since ancient times.

General Information

Mass30.973761998Amu
Meltingpoint317.3K
Boilingpoint550.0K
Electronegativity2.19
Abundance (in earth)1050.0mg/kg
Specific Heat0.769J/(g·K)
First Ionization Energy10.4867eV
Radius2.23
Density1.82g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel4So3/2
Electron Configuration[Ne] 3s2 3p3

Isotopes

NeutronsMassAbundanceRadioactive
3130.9737619984100.0No
3231.973907640No
X
S 16

Sulfur

Latin sulphur, 'brimstone'

Earliest use before 2000 BC. Discovered by Middle East. Oldest sample from Middle East in Before AD 815.

First used at least 4,000 years ago. According to the Ebers Papyrus, a sulfur ointment was used in ancient Egypt to treat granular eyelids. Recognized as an element by Jabir ibn Hayyan before AD 815, and by Antoine Lavoisier in 1777.

General Information

Mass32.067499999999995Amu
Meltingpoint388.36K
Boilingpoint717.87K
Electronegativity2.58
Abundance (in earth)350.0mg/kg
Specific Heat0.71J/(g·K)
First Ionization Energy10.36eV
Radius2.14
Density2.067g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel3P2
Electron Configuration[Ne] 3s2 3p4

Isotopes

NeutronsMassAbundanceRadioactive
3231.972071174494.99No
3332.97145890980.75No
3433.9678674.25No
3635.967080710.01No
3534.969032310No
X
Cl 17

Chlorine

Greek chlōrós, 'greenish yellow'

Observed or predicted by W. Scheele in 1774. Isolated by W. Scheele in 1774.

Obtained it from hydrochloric acid, but thought it was an oxide. Only in 1808 did Humphry Davy recognize it as an element.

General Information

Mass35.451499999999996Amu
Meltingpoint171.6K
Boilingpoint239.11K
Electronegativity3.16
Abundance (in earth)145.0mg/kg
Specific Heat0.479J/(g·K)
First Ionization Energy12.9676eV
Radius2.06
Density0.003214g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel2Po3/2
Electron Configuration[Ne] 3s2 3p5

Isotopes

NeutronsMassAbundanceRadioactive
3534.9688526875.76No
3736.965902624.24No
X
Ar 18

Argon

Greek argós, 'idle' (because of its inertness)

Observed or predicted by Lord Rayleigh and W. Ramsay in 1894. Isolated by Lord Rayleigh and W. Ramsay in 1894.

They discovered the gas by comparing the molecular weights of nitrogen prepared by liquefaction from air and nitrogen prepared by chemical means. It is the first noble gas to be isolated.

General Information

Mass39.8775Amu
Meltingpoint83.8K
Boilingpoint87.3K
Electronegativity-
Abundance (in earth)3.5mg/kg
Specific Heat0.52J/(g·K)
First Ionization Energy15.7596eV
Radius1.97
Density0.0017837g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration[Ne] 3s2 3p6

Isotopes

NeutronsMassAbundanceRadioactive
3635.9675451050.3365No
3837.962732110.0632No
4039.962383123799.6003No
X
K 19

Potassium

New Latin potassa, 'potash' (the symbol K is derived from Latin kalium)

Observed or predicted by H. Davy in 1807. Isolated by H. Davy in 1807.

Davy discovered it by using electrolysis on potash.

General Information

Mass39.0983Amu
Meltingpoint336.53K
Boilingpoint1032.0K
Electronegativity0.82
Abundance (in earth)20900.0mg/kg
Specific Heat0.757J/(g·K)
First Ionization Energy4.3407eV
Radius2.34
Density0.862g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration[Ar] 4s

Isotopes

NeutronsMassAbundanceRadioactive
3938.96370648693.2581No
4039.963998170.0117Yes
4140.9618252586.7302No
4241.962402310No
4342.96073470No
X
Ca 20

Calcium

Latin calx, 'lime'

Observed or predicted by H. Davy in 1808. Isolated by H. Davy in 1808.

Davy discovered the metal by electrolysis of quicklime.

General Information

Mass40.078Amu
Meltingpoint1115.0K
Boilingpoint1757.0K
Electronegativity1.0
Abundance (in earth)41500.0mg/kg
Specific Heat0.647J/(g·K)
First Ionization Energy6.1132eV
Radius2.7
Density1.54g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration[Ar] 4s2

Isotopes

NeutronsMassAbundanceRadioactive
4039.96259086396.941No
4241.958617830.647No
4342.958766440.135No
4443.95548162.086No
4645.9536890.004No
4847.952522770.187Yes
4544.95618640No
4746.95454240No
X
Sc 21

Scandium

Latin Scandia, 'Scandinavia'

Observed or predicted by F. Nilson in 1879. Isolated by F. Nilson in 1879.

Nilson split Marignac's ytterbia into pure ytterbia and a new element that matched Mendeleev's 1871 predicted eka-boron.

General Information

Mass44.955908Amu
Meltingpoint1814.0K
Boilingpoint3109.0K
Electronegativity1.36
Abundance (in earth)22.0mg/kg
Specific Heat0.568J/(g·K)
First Ionization Energy6.5615eV
Radius2.63
Density2.989g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel2D3/2
Electron Configuration[Ar] 3d 4s2

Isotopes

NeutronsMassAbundanceRadioactive
4544.9559083100.0No
X
Ti 22

Titanium

Titans, the sons of the Earth goddess of Greek mythology

Observed or predicted by W. Gregor in 1791. Isolated by J. Berzelius in 1825.

Gregor found an oxide of a new metal in ilmenite; Klaproth independently discovered the element in rutile in 1795 and named it. The pure metallic form was only obtained in 1910 by Matthew A. Hunter.

General Information

Mass47.867Amu
Meltingpoint1941.0K
Boilingpoint3560.0K
Electronegativity1.54
Abundance (in earth)5650.0mg/kg
Specific Heat0.523J/(g·K)
First Ionization Energy6.8281eV
Radius2.57
Density4.54g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel3F2
Electron Configuration[Ar] 3d2 4s2

Isotopes

NeutronsMassAbundanceRadioactive
4645.95262778.25No
4746.95175887.44No
4847.94794273.72No
4948.94786575.41No
5049.94478695.18No
X
V 23

Vanadium

Vanadis, an Old Norse name for the Scandinavian goddess Freyja

Observed or predicted by M. del Río in 1801. Isolated by N.G.Sefström in 1830.

Río found the metal in vanadinite but retracted the claim after Hippolyte Victor Collet-Descotils disputed it. Sefström isolated and named it, and later it was shown that Río had been right in the first place.

General Information

Mass50.9415Amu
Meltingpoint2183.0K
Boilingpoint3680.0K
Electronegativity1.63
Abundance (in earth)120.0mg/kg
Specific Heat0.489J/(g·K)
First Ionization Energy6.7462eV
Radius2.52
Density6.11g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel4F3/2
Electron Configuration[Ar] 3d3 4s2

Isotopes

NeutronsMassAbundanceRadioactive
5049.9471560.25Yes
5150.94395799.75No
X
Cr 24

Chromium

Greek chróma, 'colour'

Observed or predicted by N. Vauquelin in 1794. Isolated by N. Vauquelin in 1797.

Vauquelin discovered the trioxide in crocoite ore, and later isolated the metal by heating the oxide in a charcoal oven.

General Information

Mass51.9961Amu
Meltingpoint2180.0K
Boilingpoint2944.0K
Electronegativity1.66
Abundance (in earth)102.0mg/kg
Specific Heat0.449J/(g·K)
First Ionization Energy6.7665eV
Radius2.33
Density7.15g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel7S3
Electron Configuration[Ar] 3d5 4s

Isotopes

NeutronsMassAbundanceRadioactive
5049.94604184.345No
5251.940506283.789No
5352.94064819.501No
5453.93887922.365No
5150.9447650No
X
Mn 25

Manganese

Corrupted from magnesia negra; see Magnesium

Observed or predicted by W. Scheele in 1774. Isolated by G. Gahn in 1774.

Distinguished pyrolusite as the calx of a new metal. Ignatius Gottfred Kaim also discovered the new metal in 1770, as did Scheele in 1774. It was isolated by reduction of manganese dioxide with carbon.

General Information

Mass54.938043Amu
Meltingpoint1519.0K
Boilingpoint2334.0K
Electronegativity1.55
Abundance (in earth)950.0mg/kg
Specific Heat0.479J/(g·K)
First Ionization Energy7.434eV
Radius2.42
Density7.44g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel6S5/2
Electron Configuration[Ar] 3d5 4s2

Isotopes

NeutronsMassAbundanceRadioactive
5554.9380439100.0No
5453.94035760No
X
Fe 26

Iron

English word (the symbol Fe is derived from Latin ferrum)

Earliest use before 5000 BC. Discovered by Middle East. Oldest sample from Egypt in 4000 BC.

There is evidence that iron was known from before 5000 BC. The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron age around 1200 BC and the prominent use of iron for tools and weapons.

General Information

Mass55.845Amu
Meltingpoint1811.0K
Boilingpoint3134.0K
Electronegativity1.83
Abundance (in earth)56300.0mg/kg
Specific Heat0.449J/(g·K)
First Ionization Energy7.9024eV
Radius2.26
Density7.874g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel5D4
Electron Configuration[Ar] 3d6 4s2

Isotopes

NeutronsMassAbundanceRadioactive
5453.9396095.845No
5655.934936391.754No
5756.93539282.119No
5857.93327440.282No
5251.9481130No
5554.9382920No
5958.93487430No
X
Co 27

Cobalt

German Kobold, 'goblin'

Observed or predicted by G. Brandt in 1735. Isolated by G. Brandt in 1735.

Proved that the blue color of glass is due to a new kind of metal and not bismuth as thought previously.

General Information

Mass58.933194Amu
Meltingpoint1768.0K
Boilingpoint3200.0K
Electronegativity1.88
Abundance (in earth)25.0mg/kg
Specific Heat0.421J/(g·K)
First Ionization Energy7.881eV
Radius2.22
Density8.86g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel4F9/2
Electron Configuration[Ar] 3d7 4s2

Isotopes

NeutronsMassAbundanceRadioactive
5958.9331943100.0No
5756.93629060No
5857.93575210No
6059.93381630No
X
Ni 28

Nickel

Nickel, a mischievous sprite of German miner mythology

Observed or predicted by F. Cronstedt in 1751. Isolated by F. Cronstedt in 1751.

Found by attempting to extract copper from the mineral known as fake copper (now known as niccolite).

General Information

Mass58.6934Amu
Meltingpoint1728.0K
Boilingpoint3186.0K
Electronegativity1.91
Abundance (in earth)84.0mg/kg
Specific Heat0.444J/(g·K)
First Ionization Energy7.6399eV
Radius2.19
Density8.912g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel3F4
Electron Configuration[Ar] 3d8 4s2

Isotopes

NeutronsMassAbundanceRadioactive
5857.935342468.0769No
6059.930785926.2231No
6160.93105561.1399No
6261.92834543.6345No
6463.92796680.9256No
5958.93434620No
6362.92966960No
X
Cu 29

Copper

English word, from Latin cuprum, from Ancient Greek Kýpros 'Cyprus'

Earliest use 9000 BC. Discovered by Middle East. Oldest sample from Anatolia in 6000 BC.

Copper was probably the first metal mined and crafted by humans. It was originally obtained as a native metal and later from the smelting of ores. Earliest estimates of the discovery of copper suggest around 9000 BC in the Middle East. It was one of the most important materials to humans throughout the Chalcolithic and Bronze Ages. Copper beads dating from 6000 BC have been found in Çatal Höyük, Anatolia and the archaeological site of Belovode on the Rudnik mountain in Serbia contains the world's oldest securely dated evidence of copper smelting from 5000 BC.

General Information

Mass63.546Amu
Meltingpoint1357.77K
Boilingpoint2835.0K
Electronegativity1.9
Abundance (in earth)60.0mg/kg
Specific Heat0.385J/(g·K)
First Ionization Energy7.7264eV
Radius2.17
Density8.96g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel2S1/2
Electron Configuration[Ar] 3d10 4s

Isotopes

NeutronsMassAbundanceRadioactive
6362.929597769.15No
6564.927789730.85No
6463.92976430No
X
Zn 30

Zinc

Most likely from German Zinke, 'prong' or 'tooth', though some suggest Persian sang, 'stone'

Earliest use before 1000 BC. Discovered by Indian metallurgists. Oldest sample from Indian subcontinent in 1000 BC.

Used as a component of brass since antiquity (before 1000 BC) by Indian metallurgists, but its true nature was not understood in ancient times. Identified as a distinct metal in the Rasaratna Samuccaya around the 14th century of the Christian era and by the alchemist Paracelsus in 1526. Isolated by Andreas Sigismund Marggraf in 1746.

General Information

Mass65.38Amu
Meltingpoint692.88K
Boilingpoint1180.0K
Electronegativity1.65
Abundance (in earth)70.0mg/kg
Specific Heat0.388J/(g·K)
First Ionization Energy9.3942eV
Radius2.22
Density7.134g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel1S0
Electron Configuration[Ar] 3d10 4s2

Isotopes

NeutronsMassAbundanceRadioactive
6463.92914248.268No
6665.926033827.975No
6766.92712774.102No
6867.924844619.024No
7069.92531920.631No
6564.92924080No
X
Ga 31

Gallium

Latin Gallia, 'France'

Observed or predicted by P. E. L. de Boisbaudran in 1875. Isolated by P. E. L. de Boisbaudran.

Boisbaudran observed on a pyrenea blende sample some emission lines corresponding to the eka-aluminium that was predicted by Mendeleev in 1871 and subsequently isolated the element by electrolysis.

General Information

Mass69.723Amu
Meltingpoint302.9146K
Boilingpoint2673.0K
Electronegativity1.81
Abundance (in earth)19.0mg/kg
Specific Heat0.371J/(g·K)
First Ionization Energy5.9993eV
Radius2.33
Density5.907g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel2Po1/2
Electron Configuration[Ar] 3d10 4s2 4p

Isotopes

NeutronsMassAbundanceRadioactive
6968.925573560.108No
7170.924702639.892No
6766.92820250No
6867.92798050No
X
Ge 32

Germanium

Latin Germania, 'Germany'

Observed or predicted by C. A. Winkler in 1886.

In February 1886 Winkler found in argyrodite the eka-silicon that Mendeleev had predicted in 1871.

General Information

Mass72.63Amu
Meltingpoint1211.4K
Boilingpoint3106.0K
Electronegativity2.01
Abundance (in earth)1.5mg/kg
Specific Heat0.32J/(g·K)
First Ionization Energy7.8994eV
Radius2.34
Density5.323g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel3P0
Electron Configuration[Ar] 3d10 4s2 4p2

Isotopes

NeutronsMassAbundanceRadioactive
7069.924248820.38No
7271.9220758327.31No
7372.923458967.76No
7473.92117776136.72No
7675.9214027267.83Yes
6867.92809530No
X
As 33

Arsenic

French arsenic, from Greek arsenikón 'yellow arsenic' (influenced by arsenikós, 'masculine' or 'virile'), from a West Asian wanderword ultimately from Old Iranian *zarniya-ka, 'golden'

Earliest use before AD 815. Discovered by Middle-Eastern alchemists. Oldest sample from Middle East in Before AD 815.

The use of metallic arsenic was described by the Egyptian alchemist Zosimos. The purification of arsenic was later described by Persian alchemist Jabir ibn Hayyan. Albertus Magnus (c. 1200-1280) is typically credited with the description of the metalloid in the West.

General Information

Mass74.921595Amu
Meltingpoint1090K
Boilingpoint887.0K
Electronegativity2.18
Abundance (in earth)1.8mg/kg
Specific Heat0.329J/(g·K)
First Ionization Energy9.7886eV
Radius2.31
Density5.776g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel4So3/2
Electron Configuration[Ar] 3d10 4s2 4p3

Isotopes

NeutronsMassAbundanceRadioactive
7574.9215946100.0No
X
Se 34

Selenium

Greek selḗnē, 'moon'

Observed or predicted by J. Berzelius and G. Gahn in 1817. Isolated by J. Berzelius and G. Gahn in 1817.

While working with lead they discovered a substance that they thought was tellurium, but realized after more investigation that it was different.

General Information

Mass78.971Amu
Meltingpoint453.0K
Boilingpoint958.0K
Electronegativity2.55
Abundance (in earth)0.05mg/kg
Specific Heat0.321J/(g·K)
First Ionization Energy9.7524eV
Radius2.24
Density4.809g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel3P2
Electron Configuration[Ar] 3d10 4s2 4p4

Isotopes

NeutronsMassAbundanceRadioactive
7473.9224759340.89No
7675.9192137049.37No
7776.919914157.63No
7877.9173092823.77No
8079.916521849.61No
8281.91669958.73Yes
7574.922522870No
7978.918499290No
X
Br 35

Bromine

Greek brômos, 'stench'

Observed or predicted by J. Balard and C. Löwig in 1825. Isolated by J. Balard and C. Löwig in 1825.

They both discovered the element in the autumn of 1825. Balard published his results the next year, but Löwig did not publish until 1827.

General Information

Mass79.904Amu
Meltingpoint265.8K
Boilingpoint332.0K
Electronegativity2.96
Abundance (in earth)2.4mg/kg
Specific Heat0.474J/(g·K)
First Ionization Energy11.8138eV
Radius2.19
Density3.122g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel2Po3/2
Electron Configuration[Ar] 3d10 4s2 4p5

Isotopes

NeutronsMassAbundanceRadioactive
7978.918337650.69No
8180.916289749.31No
X
Kr 36

Krypton

Greek kryptós, 'hidden'

Observed or predicted by W. Ramsay and W. Travers in 1898. Isolated by W. Ramsay and W. Travers in 1898.

On May 30, 1898, Ramsay separated a noble gas from liquid argon by difference in boiling point.

General Information

Mass83.798Amu
Meltingpoint115.79K
Boilingpoint119.93K
Electronegativity3.0
Abundance (in earth)0.0001mg/kg
Specific Heat0.248J/(g·K)
First Ionization Energy13.9996eV
Radius2.12
Density0.003733g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration[Ar] 3d10 4s2 4p6

Isotopes

NeutronsMassAbundanceRadioactive
7877.92036490.355Yes
8079.91637812.286No
8281.913482711.593No
8382.914127211.5No
8483.91149772856.987No
8685.91061062717.279No
X
Rb 37

Rubidium

Latin rubidus, 'deep red'

Observed or predicted by R. Bunsen and G. R. Kirchhoff in 1861. Isolated by Hevesy.

Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the mineral lepidolite. Bunsen never obtained a pure sample of the metal, which was later obtained by Hevesy.

General Information

Mass85.4678Amu
Meltingpoint312.46K
Boilingpoint961.0K
Electronegativity0.82
Abundance (in earth)90.0mg/kg
Specific Heat0.363J/(g·K)
First Ionization Energy4.1771eV
Radius2.4
Density1.532g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration[Kr] 5s

Isotopes

NeutronsMassAbundanceRadioactive
8584.91178973872.17No
8786.90918053127.83Yes
8685.911167430No
X
Sr 38

Strontium

Strontian, a village in Scotland

Observed or predicted by W. Cruikshank in 1787. Isolated by H. Davy in 1808.

Cruikshank and Adair Crawford in 1790 concluded that strontianite contained a new earth. It was eventually isolated electrochemically in 1808 by Humphry Davy.

General Information

Mass87.62Amu
Meltingpoint1050.0K
Boilingpoint1655.0K
Electronegativity0.95
Abundance (in earth)370.0mg/kg
Specific Heat0.301J/(g·K)
First Ionization Energy5.6949eV
Radius2.79
Density2.64g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration[Kr] 5s2

Isotopes

NeutronsMassAbundanceRadioactive
8483.91341910.56No
8685.90926069.86No
8786.90887757.0No
8887.905612582.58No
8584.9129320No
8988.90745110No
9089.907730No
X
Y 39

Yttrium

Ytterby, a village in Sweden

Observed or predicted by J. Gadolin in 1794. Isolated by H. Rose in 1843.

Discovered in gadolinite, but Mosander showed later that its ore, yttria, contained more elements. Wöhler mistakenly thought he had isolated the metal in 1828 from a volatile chloride he supposed to be yttrium chloride, but Rose proved otherwise in 1843 and correctly isolated the element himself that year.

General Information

Mass88.90584Amu
Meltingpoint1799.0K
Boilingpoint3609.0K
Electronegativity1.22
Abundance (in earth)33.0mg/kg
Specific Heat0.298J/(g·K)
First Ionization Energy6.2173eV
Radius2.74
Density4.469g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel2D3/2
Electron Configuration[Kr] 4d 5s2

Isotopes

NeutronsMassAbundanceRadioactive
8988.9058403100.0No
X
Zr 40

Zirconium

Zircon, a mineral

Observed or predicted by H. Klaproth in 1789. Isolated by J. Berzelius in 1824.

Martin Heinrich Klaproth identified a new element in zirconia.

General Information

Mass91.224Amu
Meltingpoint2128.0K
Boilingpoint4682.0K
Electronegativity1.33
Abundance (in earth)165.0mg/kg
Specific Heat0.278J/(g·K)
First Ionization Energy6.6339eV
Radius2.68
Density6.506g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel3F2
Electron Configuration[Kr] 4d2 5s2

Isotopes

NeutronsMassAbundanceRadioactive
9089.904697751.45No
9190.905639611.22No
9291.905034717.15No
9493.906310817.38No
9695.90827142.8Yes
X
Nb 41

Niobium

Niobe, daughter of king Tantalus from Greek mythology

Observed or predicted by C. Hatchett in 1801. Isolated by W. Blomstrand in 1864.

Hatchett found the element in columbite ore and named it columbium. Heinrich Rose proved in 1844 that the element is distinct from tantalum, and renamed it niobium which was officially accepted in 1949.

General Information

Mass92.90637Amu
Meltingpoint2750.0K
Boilingpoint5017.0K
Electronegativity1.6
Abundance (in earth)20.0mg/kg
Specific Heat0.265J/(g·K)
First Ionization Energy6.7589eV
Radius2.51
Density8.57g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel6D1/2
Electron Configuration[Kr] 4d4 5s

Isotopes

NeutronsMassAbundanceRadioactive
9392.906373100.0No
X
Mo 42

Molybdenum

Greek molýbdaina, 'piece of lead', from mólybdos, 'lead', due to confusuion with lead ore galena (PbS)

Observed or predicted by W. Scheele in 1778. Isolated by J. Hjelm in 1781.

Scheele recognised the metal as a constituent of molybdena.

General Information

Mass95.95Amu
Meltingpoint2896.0K
Boilingpoint4912.0K
Electronegativity2.16
Abundance (in earth)1.2mg/kg
Specific Heat0.251J/(g·K)
First Ionization Energy7.0924eV
Radius2.44
Density10.22g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel7S3
Electron Configuration[Kr] 4d5 5s

Isotopes

NeutronsMassAbundanceRadioactive
9291.90680814.77No
9493.90508499.23No
9594.905838815.9No
9695.904676116.68No
9796.90601819.56No
9897.905404824.19No
10099.90747189.67Yes
9998.90770850No
X
Tc 43

Technetium

Greek tekhnētós, 'artificial'

Observed or predicted by C. Perrier and E. Segrè in 1937. Isolated by C. Perrier & E.Segrè in 1937.

The two discovered a new element in a molybdenum sample that was used in a cyclotron, the first synthetic element to be discovered, though it was later found out that it does occur naturally in minuscule trace quantities. It had been predicted by Mendeleev in 1871 as eka-manganese.

General Information

Mass98Amu
Meltingpoint2430.0K
Boilingpoint4538.0K
Electronegativity1.9
Abundance (in earth)3e-09mg/kg
Specific Heat-J/(g·K)
First Ionization Energy7.28eV
Radius2.41
Density11.5g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel6S5/2
Electron Configuration[Kr] 4d5 5s2

Isotopes

NeutronsMassAbundanceRadioactive
9796.9063670Yes, 4.21 y
9897.9072120Yes, 4.2 y
9998.90625080No
X
Ru 44

Ruthenium

New Latin Ruthenia, 'Russia'

Observed or predicted by K. Claus in 1844. Isolated by K. Claus in 1844.

Gottfried Wilhelm Osann thought that he found three new metals in Russian platinum samples, and in 1844 Karl Karlovich Klaus confirmed that there was a new element.

General Information

Mass101.07Amu
Meltingpoint2607.0K
Boilingpoint4423.0K
Electronegativity2.2
Abundance (in earth)0.001mg/kg
Specific Heat0.238J/(g·K)
First Ionization Energy7.3605eV
Radius2.37
Density12.37g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel5F5
Electron Configuration[Kr] 4d7 5s

Isotopes

NeutronsMassAbundanceRadioactive
9695.90759035.54No
9897.9052871.87No
9998.905934112.76No
10099.904214312.6No
101100.905576917.06No
102101.904344131.55No
104103.905427518.62No
106105.9073290No
X
Rh 45

Rhodium

Greek rhodóeis, 'rose-coloured', from rhódon, 'rose'

Observed or predicted by H. Wollaston in 1804. Isolated by H. Wollaston in 1804.

Wollaston discovered and isolated it from crude platinum samples from South America.

General Information

Mass102.90549Amu
Meltingpoint2237.0K
Boilingpoint3968.0K
Electronegativity2.28
Abundance (in earth)0.001mg/kg
Specific Heat0.243J/(g·K)
First Ionization Energy7.4589eV
Radius2.33
Density12.41g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel4F9/2
Electron Configuration[Kr] 4d8 5s

Isotopes

NeutronsMassAbundanceRadioactive
103102.905498100.0No
X
Pd 46

Palladium

The asteroid Pallas, considered a planet at the time

Observed or predicted by W. H. Wollaston in 1802. Isolated by W. H. Wollaston in 1802.

Wollaston discovered it in samples of platinum from South America, but did not publish his results immediately. He had intended to name it after the newly discovered asteroid, Ceres, but by the time he published his results in 1804, cerium had taken that name. Wollaston named it after the more recently discovered asteroid Pallas.

General Information

Mass106.42Amu
Meltingpoint1828.05K
Boilingpoint3236.0K
Electronegativity2.2
Abundance (in earth)0.015mg/kg
Specific Heat0.244J/(g·K)
First Ionization Energy8.3369eV
Radius2.15
Density12.02g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel1S0
Electron Configuration[Kr] 4d10

Isotopes

NeutronsMassAbundanceRadioactive
102101.90560221.02No
104103.904030511.14No
105104.905079622.33No
106105.903480427.33No
108107.903891626.46No
110109.905172211.72No
X
Ag 47

Silver

English word (The symbol is derived from Latin argentum)

Earliest use before 5000 BC. Discovered by Asia Minor. Oldest sample from Asia Minor in ca. 4000 BC.

Estimated to have been discovered in Asia Minor shortly after copper and gold.

General Information

Mass107.8682Amu
Meltingpoint1234.93K
Boilingpoint2435.0K
Electronegativity1.93
Abundance (in earth)0.075mg/kg
Specific Heat0.235J/(g·K)
First Ionization Energy7.5762eV
Radius2.25
Density10.501g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel2S1/2
Electron Configuration[Kr] 4d10 5s

Isotopes

NeutronsMassAbundanceRadioactive
107106.905091651.839No
109108.904755348.161No
X
Cd 48

Cadmium

New Latin cadmia, from King Kadmos

Observed or predicted by S. L Hermann, F. Stromeyer, and J.C.H. Roloff in 1817. Isolated by S. L Hermann, F. Stromeyer, and J.C.H. Roloff in 1817.

All three found an unknown metal in a sample of zinc oxide from Silesia, but the name that Stromeyer gave became the accepted one.

General Information

Mass112.414Amu
Meltingpoint594.22K
Boilingpoint1040.0K
Electronegativity1.69
Abundance (in earth)0.159mg/kg
Specific Heat0.232J/(g·K)
First Ionization Energy8.9938eV
Radius2.38
Density8.69g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel1S0
Electron Configuration[Kr] 4d10 5s2

Isotopes

NeutronsMassAbundanceRadioactive
106105.90645991.25No
108107.90418340.89No
110109.903006612.49No
111110.904182912.8No
112111.902762924.13No
113112.904408112.22Yes
114113.903365128.73No
116115.904763157.49Yes
X
In 49

Indium

Latin indicum, 'indigo' (colour found in its spectrum)

Observed or predicted by F. Reich and T. Richter in 1863. Isolated by T. Richter in 1867.

Reich and Richter First identified it in sphalerite by its bright indigo-blue spectroscopic emission line. Richter isolated the metal several years later.

General Information

Mass114.818Amu
Meltingpoint429.75K
Boilingpoint2345.0K
Electronegativity1.78
Abundance (in earth)0.25mg/kg
Specific Heat0.233J/(g·K)
First Ionization Energy5.7864eV
Radius2.46
Density7.31g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel2Po1/2
Electron Configuration[Kr] 4d10 5s2 5p

Isotopes

NeutronsMassAbundanceRadioactive
113112.90406184.29No
115114.90387877695.71Yes
111110.9051080No
X
Sn 50

Tin

English word (The symbol is derived from Latin stannum)

Earliest use 3500 BC. Discovered by Asia Minor. Oldest sample from Kestel in 2000 BC.

First smelted in combination with copper around 3500 BC to produce bronze (and thus giving place to the Bronze Age in those places where Iron Age did not intrude directly on Neolithic of the Stone Age).[clarification needed] Kestel, in southern Turkey, is the site of an ancient Cassiterite mine that was used from 3250 to 1800 BC. The oldest artifacts date from around 2000 BC.

General Information

Mass118.71Amu
Meltingpoint505.08K
Boilingpoint2875.0K
Electronegativity1.96
Abundance (in earth)2.3mg/kg
Specific Heat0.228J/(g·K)
First Ionization Energy7.3439eV
Radius2.48
Density7.287g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel3P0
Electron Configuration[Kr] 4d10 5s2 5p2

Isotopes

NeutronsMassAbundanceRadioactive
112111.90482390.97No
114113.90278270.66No
115114.9033446990.34No
116115.901742814.54No
117116.9029547.68No
118117.901606624.22No
119118.90331128.59No
120119.902201632.58No
122121.90344384.63No
124123.90527665.79No
113112.90517570No
X
Sb 51

Antimony

Latin antimonium, the origin of which is uncertain: folk etymologies suggest it is derived from Greek antí ('against') + mónos ('alone'), or Old French anti-moine, 'Monk's bane', but it could plausibly be from or related to Arabic ʾiṯmid, 'antimony', reformatted as a Latin word. (The symbol is derived from Latin stibium 'stibnite'.)

Earliest use before AD 815. Discovered by Jabir ibn Hayyan. Oldest sample from Middle East in Before AD 815.

Dioscorides and Pliny both describe the accidental production of metallic antimony from stibnite, but only seem to recognize the metal as lead. The intentional isolation of antimony is described by Persian alchemist Jabir ibn Hayyan. In Europe, the metal was being produced and used by 1540, when it was described by Vannoccio Biringuccio.

General Information

Mass121.76Amu
Meltingpoint903.78K
Boilingpoint1860.0K
Electronegativity2.05
Abundance (in earth)0.2mg/kg
Specific Heat0.207J/(g·K)
First Ionization Energy8.6084eV
Radius2.46
Density6.685g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel4So3/2
Electron Configuration[Kr] 4d10 5s2 5p3

Isotopes

NeutronsMassAbundanceRadioactive
121120.90381257.21No
123122.904213242.79No
X
Te 52

Tellurium

Latin tellus, 'the ground, earth'

Observed or predicted by F.-J.M. von Reichenstein in 1782. Isolated by H. Klaproth.

Muller observed it as an impurity in gold ores from Transylvania.

General Information

Mass127.6Amu
Meltingpoint722.66K
Boilingpoint1261.0K
Electronegativity2.1
Abundance (in earth)0.001mg/kg
Specific Heat0.202J/(g·K)
First Ionization Energy9.0096eV
Radius2.42
Density6.232g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel3P2
Electron Configuration[Kr] 4d10 5s2 5p4

Isotopes

NeutronsMassAbundanceRadioactive
120119.9040590.09No
122121.90304352.55No
123122.90426980.89No
124123.90281714.74No
125124.90442997.07No
126125.903310918.84No
128127.904461331.74Yes
130129.90622274834.08Yes
X
I 53

Iodine

French iode, from Greek ioeidḗs, 'violet')

Observed or predicted by B. Courtois in 1811. Isolated by B. Courtois in 1811.

Courtois discovered it in the ashes of seaweed.

General Information

Mass126.90447Amu
Meltingpoint386.85K
Boilingpoint457.4K
Electronegativity2.66
Abundance (in earth)0.45mg/kg
Specific Heat0.214J/(g·K)
First Ionization Energy10.4513eV
Radius2.38
Density4.93g/cm3
TypeNonmetal
SubtypeNonmetal
Groundlevel2Po3/2
Electron Configuration[Kr] 4d10 5s2 5p5

Isotopes

NeutronsMassAbundanceRadioactive
127126.904472100.0No
123122.9055890No
125124.90462940No
129128.9049840No
131130.90612630No
X
Xe 54

Xenon

Greek xénon, neuter form of xénos 'strange'

Observed or predicted by W. Ramsay and W. Travers in 1898. Isolated by W. Ramsay and W. Travers in 1898.

On July 12, 1898 Ramsay separated a third noble gas within three weeks, from liquid argon by difference in boiling point.

General Information

Mass131.293Amu
Meltingpoint161.4K
Boilingpoint165.03K
Electronegativity2.6
Abundance (in earth)3e-05mg/kg
Specific Heat0.158J/(g·K)
First Ionization Energy12.1298eV
Radius2.32
Density0.005887g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration[Kr] 4d10 5s2 5p6

Isotopes

NeutronsMassAbundanceRadioactive
124123.9058920.0952No
126125.9042980.089No
128127.9035311.9102No
129128.90478086126.4006No
130129.9035093494.071No
131130.9050840621.2324No
132131.90415508626.9086No
134133.905394710.4357No
136135.9072144848.8573Yes
X
Cs 55

Caesium

Latin caesius, 'sky-blue'

Observed or predicted by R. Bunsen and R. Kirchhoff in 1860. Isolated by C. Setterberg in 1882.

Bunsen and Kirchhoff were the first to suggest finding new elements by spectrum analysis. They discovered caesium by its two blue emission lines in a sample of Dürkheim mineral water. The pure metal was eventually isolated in 1882 by Setterberg.

General Information

Mass132.90545196Amu
Meltingpoint301.59K
Boilingpoint944.0K
Electronegativity0.79
Abundance (in earth)3.0mg/kg
Specific Heat0.242J/(g·K)
First Ionization Energy3.8939eV
Radius2.49
Density1.873g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration[Xe] 6s

Isotopes

NeutronsMassAbundanceRadioactive
133132.905451961100.0No
129128.9060660No
134133.9067185030No
136135.90731140No
137136.90708920No
X
Ba 56

Barium

Greek barýs, 'heavy'

Observed or predicted by W. Scheele in 1772. Isolated by H. Davy in 1808.

Scheele distinguished a new earth (BaO) in pyrolusite and Davy isolated the metal by electrolysis.

General Information

Mass137.327Amu
Meltingpoint1000.0K
Boilingpoint2170.0K
Electronegativity0.89
Abundance (in earth)425.0mg/kg
Specific Heat0.204J/(g·K)
First Ionization Energy5.2117eV
Radius2.93
Density3.594g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration[Xe] 6s2

Isotopes

NeutronsMassAbundanceRadioactive
130129.90632070.106Yes
132131.90506110.101No
134133.904508182.417No
135134.905688386.592No
136135.904575737.854No
137136.905827111.232No
138137.90524771.698No
133132.90600740No
140139.9106060No
X
La 57

Lanthanum

Greek lanthánein, 'to lie hidden'

Observed or predicted by G. Mosander in 1838. Isolated by G. Mosander in 1841.

Mosander found a new element in samples of ceria and published his results in 1842, but later he showed that this lanthana contained four more elements.

General Information

Mass138.90547Amu
Meltingpoint1193.0K
Boilingpoint3737.0K
Electronegativity1.1
Abundance (in earth)39.0mg/kg
Specific Heat0.195J/(g·K)
First Ionization Energy5.5769eV
Radius2.84
Density6.145g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel2D3/2
Electron Configuration[Xe] 5d 6s2

Isotopes

NeutronsMassAbundanceRadioactive
138137.9071150.09Yes
139138.906356399.91No
X
Ce 58

Cerium

The dwarf planet Ceres, considered a planet at the time

Observed or predicted by H. Klaproth, J. Berzelius, and W. Hisinger in 1803. Isolated by G. Mosander in 1838.

Berzelius and Hisinger discovered the element in ceria and named it after the newly discovered asteroid (then considered a planet), Ceres. Klaproth discovered it simultaneously and independently in some tantalum samples. Mosander proved later that the samples of all three researchers had at least another element in them, lanthanum.

General Information

Mass140.116Amu
Meltingpoint1068.0K
Boilingpoint3716.0K
Electronegativity1.12
Abundance (in earth)66.5mg/kg
Specific Heat0.192J/(g·K)
First Ionization Energy5.5387eV
Radius2.82
Density6.77g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel1Go4
Electron Configuration[Xe] 4f 5d 6s2

Isotopes

NeutronsMassAbundanceRadioactive
136135.90712920.185No
138137.9059910.251No
140139.905443188.45No
142141.909250411.114No
141140.90828070No
144143.9136530No
X
Pr 59

Praseodymium

Greek prásios dídymos, 'green twin'

Observed or predicted by C. A. von Welsbach in 1885.

Carl Auer von Welsbach discovered two new distinct elements in Mosander's didymia: praseodymium and neodymium.

General Information

Mass140.90766Amu
Meltingpoint1208.0K
Boilingpoint3793.0K
Electronegativity1.13
Abundance (in earth)9.2mg/kg
Specific Heat0.193J/(g·K)
First Ionization Energy5.473eV
Radius2.86
Density6.773g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel4Io9/2
Electron Configuration[Xe] 4f3 6s2

Isotopes

NeutronsMassAbundanceRadioactive
141140.9076576100.0No
X
Nd 60

Neodymium

Greek néos dídymos, 'new twin'

Observed or predicted by C. A. von Welsbach in 1885.

Carl Auer von Welsbach discovered two new distinct elements in Mosander's didymia: praseodymium and neodymium.

General Information

Mass144.242Amu
Meltingpoint1297.0K
Boilingpoint3347.0K
Electronegativity1.14
Abundance (in earth)41.5mg/kg
Specific Heat0.19J/(g·K)
First Ionization Energy5.525eV
Radius2.84
Density7.007g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel5I4
Electron Configuration[Xe] 4f4 6s2

Isotopes

NeutronsMassAbundanceRadioactive
142141.90772927.2No
143142.9098212.2No
144143.91009323.8Yes
145144.91257938.3No
146145.913122617.2No
148147.91689935.7No
150149.92090225.6Yes
X
Pm 61

Promethium

Prometheus of Greek mythology

Observed or predicted by S. Wu, E.G. Segrè and H. Bethe in 1942. Isolated by Charles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin, and Harold G. Richter[citation needed] in 1945.

It was probably first prepared in 1942 by bombarding neodymium and praseodymium with neutrons, but separation of the element could not be carried out. Isolation was performed under the Manhattan Project in 1945.

General Information

Mass145Amu
Meltingpoint1315.0K
Boilingpoint3273.0K
Electronegativity1.13
Abundance (in earth)2e-19mg/kg
Specific Heat-J/(g·K)
First Ionization Energy5.582eV
Radius2.83
Density7.26g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel6Ho5/2
Electron Configuration[Xe] 4f5 6s2

Isotopes

NeutronsMassAbundanceRadioactive
145144.9127560Yes, 17.7 y
147146.9151450No
X
Sm 62

Samarium

Samarskite, a mineral named after Colonel Vasili Samarsky-Bykhovets, Russian mine official

Observed or predicted by P.E.L. de Boisbaudran in 1879. Isolated by P.E.L. de Boisbaudran in 1879.

Boisbaudran noted a new earth in samarskite and named it samaria after the mineral.

General Information

Mass150.36Amu
Meltingpoint1345.0K
Boilingpoint2067.0K
Electronegativity1.17
Abundance (in earth)7.05mg/kg
Specific Heat0.197J/(g·K)
First Ionization Energy5.6437eV
Radius2.8
Density7.52g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel7F0
Electron Configuration[Xe] 4f6 6s2

Isotopes

NeutronsMassAbundanceRadioactive
144143.91200653.07No
147146.914904414.99Yes
148147.914829211.24Yes
149148.917192113.82No
150149.91728297.38No
152151.919739726.75No
154153.922216922.75No
X
Eu 63

Europium

Europe

Observed or predicted by E.-A. Demarçay in 1896. Isolated by E.-A. Demarçay in 1901.

Demarçay found spectral lines of a new element in Lecoq's samarium, and separated this element several years later.

General Information

Mass151.964Amu
Meltingpoint1099.0K
Boilingpoint1802.0K
Electronegativity1.2
Abundance (in earth)2.0mg/kg
Specific Heat0.182J/(g·K)
First Ionization Energy5.6704eV
Radius2.8
Density5.243g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel8So7/2
Electron Configuration[Xe] 4f7 6s2

Isotopes

NeutronsMassAbundanceRadioactive
151150.919857847.81Yes
153152.92123852.19No
X
Gd 64

Gadolinium

Gadolinite, a mineral named after Johan Gadolin, Finnish chemist, physicist and mineralogist

Observed or predicted by J. C. G. de Marignac in 1880. Isolated by P.E.L. de Boisbaudran in 1886.

Marignac initially observed the new earth in terbia, and later Boisbaudran obtained a pure sample from samarskite.

General Information

Mass157.25Amu
Meltingpoint1585.0K
Boilingpoint3546.0K
Electronegativity1.2
Abundance (in earth)6.2mg/kg
Specific Heat0.236J/(g·K)
First Ionization Energy6.1498eV
Radius2.77
Density7.895g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel9Do2
Electron Configuration[Xe] 4f7 5d 6s2

Isotopes

NeutronsMassAbundanceRadioactive
152151.91979950.2No
154153.92087412.18No
155154.922630514.8No
156155.922131220.47No
157156.923968615.65No
158157.924112324.84No
160159.927062421.86No
X
Tb 65

Terbium

Ytterby, a village in Sweden

Observed or predicted by G. Mosander in 1843. Isolated by J.C.G. de Marignac in 1886.

Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too.

General Information

Mass158.925354Amu
Meltingpoint1629.0K
Boilingpoint3503.0K
Electronegativity1.2
Abundance (in earth)1.2mg/kg
Specific Heat0.182J/(g·K)
First Ionization Energy5.8638eV
Radius2.76
Density8.229g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel6Ho15/2
Electron Configuration[Xe] 4f9 6s2

Isotopes

NeutronsMassAbundanceRadioactive
159158.9253547100.0No
X
Dy 66

Dysprosium

Greek dysprósitos, 'hard to get'

Observed or predicted by P.E.L. de Boisbaudran in 1886.

De Boisbaudran found a new earth in erbia.

General Information

Mass162.5Amu
Meltingpoint1680.0K
Boilingpoint2840.0K
Electronegativity1.22
Abundance (in earth)5.2mg/kg
Specific Heat0.17J/(g·K)
First Ionization Energy5.9389eV
Radius2.75
Density8.55g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel5I8
Electron Configuration[Xe] 4f10 6s2

Isotopes

NeutronsMassAbundanceRadioactive
156155.92428470.056No
158157.9244160.095No
160159.92520462.329No
161160.926940518.889No
162161.926805625.475No
163162.928738324.896No
164163.929181928.26No
X
Ho 67

Holmium

New Latin Holmia, 'Stockholm'

Observed or predicted by J.-L. Soret and M. Delafontaine in 1878. Isolated by T. Cleve in 1879.

Soret found it in samarskite and later, Per Teodor Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium. Delafontaine's philippium turned out to be identical to what Soret found.

General Information

Mass164.930328Amu
Meltingpoint1734.0K
Boilingpoint2993.0K
Electronegativity1.23
Abundance (in earth)1.3mg/kg
Specific Heat0.165J/(g·K)
First Ionization Energy6.0215eV
Radius2.73
Density8.795g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel4Io15/2
Electron Configuration[Xe] 4f11 6s2

Isotopes

NeutronsMassAbundanceRadioactive
165164.9303288100.0No
X
Er 68

Erbium

Ytterby, a village in Sweden

Observed or predicted by G. Mosander in 1843. Isolated by T. Cleve in 1879.

Mosander managed to split the old yttria into yttria proper and erbia, and later terbia too.

General Information

Mass167.259Amu
Meltingpoint1802.0K
Boilingpoint3141.0K
Electronegativity1.24
Abundance (in earth)3.5mg/kg
Specific Heat0.168J/(g·K)
First Ionization Energy6.1077eV
Radius2.72
Density9.066g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel3H6
Electron Configuration[Xe] 4f12 6s2

Isotopes

NeutronsMassAbundanceRadioactive
162161.92878840.139No
164163.92920881.601No
166165.930299533.503No
167166.932054622.869No
168167.932376726.978No
170169.935470214.91No
X
Tm 69

Thulium

Thule, the ancient name for an unclear northern location

Observed or predicted by T. Cleve in 1879. Isolated by T. Cleve in 1879.

Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium.

General Information

Mass168.934218Amu
Meltingpoint1818.0K
Boilingpoint2223.0K
Electronegativity1.25
Abundance (in earth)0.52mg/kg
Specific Heat0.16J/(g·K)
First Ionization Energy6.1843eV
Radius2.71
Density9.321g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel2Fo7/2
Electron Configuration[Xe] 4f13 6s2

Isotopes

NeutronsMassAbundanceRadioactive
169168.9342179100.0No
X
Yb 70

Ytterbium

Ytterby, a village in Sweden

Observed or predicted by J.C.G. de Marignac in 1878. Isolated by C. A. von Welsbach in 1906.

On October 22, 1878, Marignac reported splitting terbia into two new earths, terbia proper and ytterbia.

General Information

Mass173.045Amu
Meltingpoint1097.0K
Boilingpoint1469.0K
Electronegativity1.1
Abundance (in earth)3.2mg/kg
Specific Heat0.155J/(g·K)
First Ionization Energy6.2542eV
Radius2.77
Density6.965g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel1S0
Electron Configuration[Xe] 4f14 6s2

Isotopes

NeutronsMassAbundanceRadioactive
168167.93388960.13No
170169.93476643.04No
171170.936330214.28No
172171.936385921.83No
173172.938215116.13No
174173.938866431.83No
176175.942576412.76No
169168.93518250No
X
Lu 71

Lutetium

Latin Lutetia, 'Paris'

Observed or predicted by C. A. von Welsbach and G. Urbain in 1906. Isolated by C. A. von Welsbach in 1906.

von Welsbach proved that the old ytterbium also contained a new element, which he named cassiopeium. Urbain also proved this simultaneously, but his samples were very impure and only contained trace quantities of the new element. Despite this, his chosen name lutetium was adopted.

General Information

Mass174.9668Amu
Meltingpoint1925.0K
Boilingpoint3675.0K
Electronegativity1.27
Abundance (in earth)0.8mg/kg
Specific Heat0.154J/(g·K)
First Ionization Energy5.4259eV
Radius2.7
Density9.84g/cm3
TypeMetal
SubtypeLanthanide
Groundlevel2D3/2
Electron Configuration[Xe] 4f14 5d 6s2

Isotopes

NeutronsMassAbundanceRadioactive
175174.940775297.41No
176175.94268972.59Yes
X
Hf 72

Hafnium

New Latin Hafnia, 'Copenhagen' (from Danish havn)

Observed or predicted by D. Coster and G. von Hevesy in 1922. Isolated by D. Coster and G. von Hevesy in 1922.

Georges Urbain claimed to have found the element in rare-earth residues, while Vladimir Vernadsky independently found it in orthite. Neither claim was confirmed due to World War I, and neither could be confirmed later, as the chemistry they reported does not match that now known for hafnium. After the war, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon. Hafnium was the last stable element to be discovered.

General Information

Mass178.486Amu
Meltingpoint2506.0K
Boilingpoint4876.0K
Electronegativity1.3
Abundance (in earth)3.0mg/kg
Specific Heat0.144J/(g·K)
First Ionization Energy6.8251eV
Radius2.64
Density13.31g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel3F2
Electron Configuration[Xe] 4f14 5d2 6s2

Isotopes

NeutronsMassAbundanceRadioactive
174173.94004610.16Yes
176175.94140765.26No
177176.943227718.6No
178177.943705827.28No
179178.945823213.62No
180179.94655735.08No
X
Ta 73

Tantalum

King Tantalus, father of Niobe from Greek mythology

Observed or predicted by G. Ekeberg in 1802.

Ekeberg found another element in minerals similar to columbite and in 1844, Heinrich Rose proved that it was distinct from niobium.

General Information

Mass180.94788Amu
Meltingpoint3290.0K
Boilingpoint5731.0K
Electronegativity1.5
Abundance (in earth)2.0mg/kg
Specific Heat0.14J/(g·K)
First Ionization Energy7.5496eV
Radius2.58
Density16.654g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel4F3/2
Electron Configuration[Xe] 4f14 5d3 6s2

Isotopes

NeutronsMassAbundanceRadioactive
180179.94746480.012Yes
181180.947995899.988No
X
W 74

Tungsten

Swedish tung sten, 'heavy stone' (The symbol W is from Wolfram, a name used for the element in many languages, originally from Middle High German wolf-rahm (wolf's foam) describing the mineral wolframite)[7]

Observed or predicted by W. Scheele in 1781. Isolated by J. and F. Elhuyar in 1783.

Scheele obtained from scheelite an oxide of a new element. The Elhuyars obtained tungstic acid from wolframite and reduced it with charcoal.

General Information

Mass183.84Amu
Meltingpoint3695.0K
Boilingpoint5828.0K
Electronegativity2.36
Abundance (in earth)1.3mg/kg
Specific Heat0.132J/(g·K)
First Ionization Energy7.864eV
Radius2.53
Density19.25g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel5D0
Electron Configuration[Xe] 4f14 5d4 6s2

Isotopes

NeutronsMassAbundanceRadioactive
180179.94671080.12Yes
182181.948203926.5No
183182.950222714.31No
184183.950930930.64No
186185.954362828.43No
X
Re 75

Rhenium

Latin Rhenus, 'the Rhine'

Observed or predicted by M. Ogawa in 1908. Isolated by M. Ogawa in 1919.

Ogawa found it in thorianite but assigned it as element 43 instead of 75 and named it nipponium. In 1925 Walter Noddack, Ida Eva Tacke and Otto Berg announced its separation from gadolinite and gave it the present name.

General Information

Mass186.207Amu
Meltingpoint3459.0K
Boilingpoint5869.0K
Electronegativity1.9
Abundance (in earth)0.0007mg/kg
Specific Heat0.137J/(g·K)
First Ionization Energy7.8335eV
Radius2.49
Density21.02g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel6S5/2
Electron Configuration[Xe] 4f14 5d5 6s2

Isotopes

NeutronsMassAbundanceRadioactive
185184.952954537.4No
187186.955750162.6Yes
X
Os 76

Osmium

Greek osmḗ, 'smell'

Observed or predicted by S. Tennant in 1803. Isolated by S. Tennant in 1803.

Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium.

General Information

Mass190.23Amu
Meltingpoint3306.0K
Boilingpoint5285.0K
Electronegativity2.2
Abundance (in earth)0.002mg/kg
Specific Heat0.13J/(g·K)
First Ionization Energy8.4382eV
Radius2.44
Density22.61g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel5D4
Electron Configuration[Xe] 4f14 5d6 6s2

Isotopes

NeutronsMassAbundanceRadioactive
184183.95248850.02Yes
186185.9538351.59Yes
187186.95574741.96No
188187.955835213.24No
189188.958144216.15No
190189.958443726.26No
192191.96147740.78No
X
Ir 77

Iridium

Iris, the Greek goddess of the rainbow

Observed or predicted by S. Tennant in 1803. Isolated by S. Tennant in 1803.

Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium, and published the iridium results in 1804.

General Information

Mass192.217Amu
Meltingpoint2719.0K
Boilingpoint4701.0K
Electronegativity2.2
Abundance (in earth)0.001mg/kg
Specific Heat0.131J/(g·K)
First Ionization Energy8.967eV
Radius2.33
Density22.56g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel4F9/2
Electron Configuration[Xe] 4f14 5d7 6s2

Isotopes

NeutronsMassAbundanceRadioactive
191190.960589337.3No
193192.962921662.7No
X
Pt 78

Platinum

Spanish platina, 'little silver', from plata 'silver'

Observed or predicted by A. de Ulloa in 1735.

First description of a metal found in South American gold was in 1557 by Julius Caesar Scaliger. Ulloa published his findings in 1748, but Sir Charles Wood also investigated the metal in 1741. First reference to it as a new metal was made by William Brownrigg in 1750.

General Information

Mass195.084Amu
Meltingpoint2041.4K
Boilingpoint4098.0K
Electronegativity2.28
Abundance (in earth)0.005mg/kg
Specific Heat0.133J/(g·K)
First Ionization Energy8.9588eV
Radius2.3
Density21.46g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel3D3
Electron Configuration[Xe] 4f14 5d9 6s

Isotopes

NeutronsMassAbundanceRadioactive
190189.959930.014Yes
192191.9610390.782No
194193.962680932.967No
195194.964791733.832No
196195.964952125.242No
198197.96789497.163No
X
Au 79

Gold

English word (the symbol Au is derived from Latin aurum)

Earliest use before 6000 BC. Discovered by Levant. Oldest sample from Nahal Qana in Before 4000 BC.

The earliest gold artifacts were discovered at the site of Nahal Qana in the Levant.

General Information

Mass196.96657Amu
Meltingpoint1337.33K
Boilingpoint3129.0K
Electronegativity2.54
Abundance (in earth)0.004mg/kg
Specific Heat0.129J/(g·K)
First Ionization Energy9.2255eV
Radius2.26
Density19.282g/cm3
TypeMetal
SubtypeTransition Metal
Groundlevel2S1/2
Electron Configuration[Xe] 4f14 5d10 6s

Isotopes

NeutronsMassAbundanceRadioactive
197196.9665688100.0No
198197.96824240No
X
Hg 80

Mercury

Mercury, Roman god of commerce, communication, and luck, known for his speed and mobility (the symbol Hg derives from the element's Latin name hydrargyrum, from Greek hydrárgyros, 'water-silver')

Earliest use 1500 BC. Discovered by Egyptians. Oldest sample from Egypt in 1500 BC.

Found in Egyptian tombs dating from 1500 BC.

General Information

Mass200.592Amu
Meltingpoint234.43K
Boilingpoint629.88K
Electronegativity2.0
Abundance (in earth)0.085mg/kg
Specific Heat0.14J/(g·K)
First Ionization Energy10.4375eV
Radius2.29
Density13.5336g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel1S0
Electron Configuration[Xe] 4f14 5d10 6s2

Isotopes

NeutronsMassAbundanceRadioactive
196195.9658330.15No
198197.96676869.97No
199198.968280616.87No
200199.968326623.1No
201200.970302813.18No
202201.970643429.86No
204203.9734946.87No
197196.9672130No
203202.97287280No
X
Tl 81

Thallium

Greek thallós, 'green shoot or twig'

Observed or predicted by W. Crookes in 1861. Isolated by C.-A. Lamy in 1862.

Shortly after the discovery of rubidium, Crookes found a new green line in a selenium sample; later that year, Lamy found the element to be metallic.

General Information

Mass204.3835Amu
Meltingpoint577.0K
Boilingpoint1746.0K
Electronegativity1.62
Abundance (in earth)0.85mg/kg
Specific Heat0.129J/(g·K)
First Ionization Energy6.1082eV
Radius2.42
Density11.85g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel2Po1/2
Electron Configuration[Xe] 4f14 5d10 6s2 6p

Isotopes

NeutronsMassAbundanceRadioactive
203202.972344629.52No
205204.974427870.48No
201200.9708220No
X
Pb 82

Lead

English word (the symbol Pb is derived from Latin plumbum)

Earliest use 7000 BC. Discovered by Africa. Oldest sample from Abydos, Egypt in 3800 BC.

It is believed that lead smelting began at least 9,000 years ago, and the oldest known artifact of lead is a statuette found at the temple of Osiris on the site of Abydos dated around 3800 BC.

General Information

Mass207.2Amu
Meltingpoint600.61K
Boilingpoint2022.0K
Electronegativity1.87
Abundance (in earth)14.0mg/kg
Specific Heat0.129J/(g·K)
First Ionization Energy7.4167eV
Radius2.49
Density11.342g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel3P0
Electron Configuration[Xe] 4f14 5d10 6s2 6p2

Isotopes

NeutronsMassAbundanceRadioactive
204203.9730441.4No
206205.974465724.1No
207206.975897322.1No
208207.976652552.4No
210209.98418890No
X
Bi 83

Bismuth

German Wismut, from weiß Masse 'white mass', unless from Arabic

Earliest use before AD 1000. Discovered by Jabirian corpus. Oldest sample from Middle East in Before AD 1000.

Described by Persian alchemist Jabir ibn Hayyan in the Jabirian corpus. Later described in Europe by Claude François Geoffroy in 1753.

General Information

Mass208.9804Amu
Meltingpoint544.7K
Boilingpoint1837.0K
Electronegativity2.02
Abundance (in earth)0.009mg/kg
Specific Heat0.122J/(g·K)
First Ionization Energy7.2855eV
Radius2.5
Density9.807g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel4So3/2
Electron Configuration[Xe] 4f14 5d10 6s2 6p3

Isotopes

NeutronsMassAbundanceRadioactive
209208.9803991100.0Yes
207206.9784710No
X
Po 84

Polonium

Latin Polonia, 'Poland' (the home country of Marie Curie)

Observed or predicted by P. and M. Curie in 1898. Isolated by W. Marckwald in 1902.

In an experiment done on July 13, 1898, the Curies noted an increased radioactivity in the uranium obtained from pitchblende, which they ascribed to an unknown element.

General Information

Mass209Amu
Meltingpoint527.0K
Boilingpoint1235.0K
Electronegativity2.0
Abundance (in earth)2e-10mg/kg
Specific Heat-J/(g·K)
First Ionization Energy8.414eV
Radius2.5
Density9.32g/cm3
TypeMetal
SubtypePosttransition Metal
Groundlevel3P2
Electron Configuration[Xe] 4f14 5d10 6s2 6p4

Isotopes

NeutronsMassAbundanceRadioactive
209208.98243080Yes, 124.0 y
210209.98287410No
X
At 85

Astatine

Greek ástatos, 'unstable'

Observed or predicted by R. Corson, R. MacKenzie and E. Segrè in 1940.

Obtained by bombarding bismuth with alpha particles. Later determined to occur naturally in minuscule quantities (<25 grams in earth's crust).

General Information

Mass210Amu
Meltingpoint575.0K
Boilingpoint610.0K
Electronegativity2.2
Abundance (in earth)3e-21mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius2.47
Density7.0g/cm3
TypeMetalloid
SubtypeMetalloid
Groundlevel2Po3/2
Electron Configuration[Xe] 4f14 5d10 6s2 6p5

Isotopes

NeutronsMassAbundanceRadioactive
210209.9871480Yes, 8.1 h
211210.98749660No
X
Rn 86

Radon

Radium emanation, originally the name of the isotope Radon-222.

Observed or predicted by E. Rutherford and R. B. Owens in 1899. Isolated by W. Ramsay and R. Whytlaw-Gray in 1910.

Rutherford and Owens discovered a radioactive gas resulting from the radioactive decay of thorium, isolated later by Ramsay and Gray. In 1900, Friedrich Ernst Dorn discovered a longer-lived isotope of the same gas from the radioactive decay of radium. Since 'radon' was first used to specifically designate Dorn's isotope before it became the name for the element, he is often mistakenly given credit for the latter instead of the former.

General Information

Mass222Amu
Meltingpoint202.0K
Boilingpoint211.3K
Electronegativity2.2
Abundance (in earth)4e-13mg/kg
Specific Heat0.094J/(g·K)
First Ionization Energy10.7485eV
Radius2.43
Density0.00973g/cm3
TypeNonmetal
SubtypeNoble Gas
Groundlevel1S0
Electron Configuration[Xe] 4f14 5d10 6s2 6p6

Isotopes

NeutronsMassAbundanceRadioactive
222222.01757820Yes, 3.8215 d
211210.9906010No
220220.01139410No
X
Fr 87

Francium

France

Observed or predicted by M. Perey in 1939.

Perey discovered it as a decay product of 227Ac. Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the 'synthetic' elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well.

General Information

Mass223Amu
Meltingpoint281.0K
Boilingpoint890.0K
Electronegativity0.7
Abundance (in earth)1e-18mg/kg
Specific Heat-J/(g·K)
First Ionization Energy4.0727eV
Radius2.58
Density1.87g/cm3
TypeMetal
SubtypeAlkali Metal
Groundlevel2S1/2
Electron Configuration[Rn] 7s

Isotopes

NeutronsMassAbundanceRadioactive
223223.0197360Yes, 22.0 min
X
Ra 88

Radium

French radium, from Latin radius, 'ray'

Observed or predicted by P. and M. Curie in 1898. Isolated by M. Curie in 1902.

The Curies reported on December 26, 1898, a new element different from polonium, which Marie later isolated from uraninite.

General Information

Mass226Amu
Meltingpoint973.0K
Boilingpoint2010.0K
Electronegativity0.9
Abundance (in earth)9e-07mg/kg
Specific Heat0.094J/(g·K)
First Ionization Energy5.2784eV
Radius2.92
Density5.5g/cm3
TypeMetal
SubtypeAlkali Earth Metal
Groundlevel1S0
Electron Configuration[Rn] 7s2

Isotopes

NeutronsMassAbundanceRadioactive
226226.02541030Yes, 1600.0 y
223223.01850230No
224224.0202120No
228228.03107070No
X
Ac 89

Actinium

Greek aktís, 'ray'

Observed or predicted by F. O. Giesel in 1902. Isolated by F. O. Giesel in 1902.

Giesel obtained from pitchblende a substance that had properties similar to those of lanthanum and named it emanium. André-Louis Debierne had previously reported the discovery of a new element actinium that was supposedly similar to titanium and thorium; the elements were mistakenly identified as being identical and Debierne's name was chosen, even though in retrospect Debierne's substance could not have included much actual element 89.

General Information

Mass227Amu
Meltingpoint1323.0K
Boilingpoint3471.0K
Electronegativity1.1
Abundance (in earth)5.5e-10mg/kg
Specific Heat0.12J/(g·K)
First Ionization Energy5.3807eV
Radius2.93
Density10.07g/cm3
TypeMetal
SubtypeActinide
Groundlevel2D3/2
Electron Configuration[Rn] 6d 7s2

Isotopes

NeutronsMassAbundanceRadioactive
227227.02775230Yes, 21.772 y
X
Th 90

Thorium

Thor, the Scandinavian god of thunder

Observed or predicted by J. Berzelius in 1829. Isolated by D. Lely, Jr. and L. Hamburger in 1914.

Berzelius obtained the oxide of a new earth in thorite.

General Information

Mass232.0377Amu
Meltingpoint2115.0K
Boilingpoint5061.0K
Electronegativity1.3
Abundance (in earth)9.6mg/kg
Specific Heat0.113J/(g·K)
First Ionization Energy6.3067eV
Radius2.89
Density11.72g/cm3
TypeMetal
SubtypeActinide
Groundlevel3F2
Electron Configuration[Rn] 6d2 7s2

Isotopes

NeutronsMassAbundanceRadioactive
230230.03313410Yes
232232.0380558100.0Yes
228228.02874130No
X
Pa 91

Protactinium

Proto- (from Greek prôtos, 'first, before') + actinium, which is produced through the radioactive decay of protactinium

Observed or predicted by O. H. Göhring and K. Fajans in 1913. Isolated by A. von Grosse in 1927.

The two obtained the first isotope of this element that had been predicted by Mendeleev in 1871 as a member of the natural decay of 238U. Originally isolated in 1900 by William Crookes, who nevertheless did not recognize that it was a new element.

General Information

Mass231.03588Amu
Meltingpoint1841.0K
Boilingpoint4300.0K
Electronegativity1.5
Abundance (in earth)1.4e-06mg/kg
Specific Heat-J/(g·K)
First Ionization Energy5.89eV
Radius2.85
Density15.37g/cm3
TypeMetal
SubtypeActinide
Groundlevel(4,3/2)11/2
Electron Configuration[Rn] 5f2 6d 7s2

Isotopes

NeutronsMassAbundanceRadioactive
231231.0358842100.0Yes
X
U 92

Uranium

Uranus, the seventh planet in the Solar System

Observed or predicted by H. Klaproth in 1789. Isolated by E.-M. Péligot in 1841.

Klaproth mistakenly identified a uranium oxide obtained from pitchblende as the element itself and named it after the recently discovered planet Uranus.

General Information

Mass238.02891Amu
Meltingpoint1405.3K
Boilingpoint4404.0K
Electronegativity1.38
Abundance (in earth)2.7mg/kg
Specific Heat0.116J/(g·K)
First Ionization Energy6.1939eV
Radius2.83
Density18.95g/cm3
TypeMetal
SubtypeActinide
Groundlevel(9/2,3/2)o6
Electron Configuration[Rn] 5f3 6d 7s2

Isotopes

NeutronsMassAbundanceRadioactive
234234.04095230.0054Yes
235235.04393010.7204Yes
238238.050788499.2742Yes
233233.03963550No
236236.04556820No
X
Np 93

Neptunium

Neptune, the eighth planet in the Solar System

Observed or predicted by E.M. McMillan and H. Abelson in 1940.

Obtained by irradiating uranium with neutrons, it is the first transuranium element discovered.

General Information

Mass237Amu
Meltingpoint917.0K
Boilingpoint4273.0K
Electronegativity1.36
Abundance (in earth)3e-12mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.2657eV
Radius2.8
Density20.45g/cm3
TypeMetal
SubtypeActinide
Groundlevel(4,3/2)11/2
Electron Configuration[Rn] 5f4 6d 7s2

Isotopes

NeutronsMassAbundanceRadioactive
237237.04817360Yes, 2144.0 y
239239.05293920No
X
Pu 94

Plutonium

The dwarf planet Pluto, considered the ninth planet in the Solar System at the time

Observed or predicted by Glenn T. Seaborg, Arthur C. Wahl, W. Kennedy and E.M. McMillan in 1940–1941.

Prepared by bombardment of uranium with deuterons.

General Information

Mass244Amu
Meltingpoint912.5K
Boilingpoint3501.0K
Electronegativity1.28
Abundance (in earth)3e-11mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.026eV
Radius2.78
Density19.84g/cm3
TypeMetal
SubtypeActinide
Groundlevel7F0
Electron Configuration[Rn] 5f6 7s2

Isotopes

NeutronsMassAbundanceRadioactive
244244.0642050Yes, 80.0 y
238238.04956010No
239239.05216360No
240240.05381380No
241241.05685170No
242242.05874280No
X
Am 95

Americium

The Americas, as the element was first synthesised on the continent, by analogy with europium

Observed or predicted by G. T. Seaborg, R. A. James, O. Morgan and A. Ghiorso in 1944.

Prepared by irradiating plutonium with neutrons during the Manhattan Project.

General Information

Mass243Amu
Meltingpoint1449.0K
Boilingpoint2880.0K
Electronegativity1.13
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy5.9738eV
Radius2.76
Density13.69g/cm3
TypeMetal
SubtypeActinide
Groundlevel8So7/2
Electron Configuration[Rn] 5f7 7s2

Isotopes

NeutronsMassAbundanceRadioactive
243243.06138130Yes, 7.364 y
241241.05682930No
X
Cm 96

Curium

Pierre Curie and Marie Curie, French physicists and chemists

Observed or predicted by Glenn T. Seaborg, Ralph A. James and Albert Ghiorso in 1944.

Prepared by bombarding plutonium with alpha particles during the Manhattan Project

General Information

Mass247Amu
Meltingpoint1613.0K
Boilingpoint3383.0K
Electronegativity1.28
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy5.9914eV
Radius-
Density13.51g/cm3
TypeMetal
SubtypeActinide
Groundlevel9Do2
Electron Configuration[Rn] 5f7 6d 7s2

Isotopes

NeutronsMassAbundanceRadioactive
247247.0703540Yes, 15.6 y
243243.06138930No
244244.06275280No
245245.06549150No
246246.06722380No
248248.072350No
X
Bk 97

Berkelium

Berkeley, California, where the element was first synthesised, by analogy with terbium

Observed or predicted by G. Thompson, A. Ghiorso and G. T. Seaborg (University of California, Berkeley) in 1949.

Created by bombardment of americium with alpha particles.

General Information

Mass247Amu
Meltingpoint1259.0K
Boilingpoint2900.0K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.1979eV
Radius-
Density14.79g/cm3
TypeMetal
SubtypeActinide
Groundlevel6Ho15/2
Electron Configuration[Rn] 5f9 7s2

Isotopes

NeutronsMassAbundanceRadioactive
247247.0703070Yes, 1.38 y
249249.07498770No
X
Cf 98

Californium

California, where the element was first synthesised

Observed or predicted by S. G. Thompson, K. Street, Jr., A. Ghiorso and G. T. Seaborg (University of California, Berkeley) in 1950.

Bombardment of curium with alpha particles.

General Information

Mass251Amu
Meltingpoint1173.0K
Boilingpoint1743K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.2817eV
Radius-
Density15.1g/cm3
TypeMetal
SubtypeActinide
Groundlevel5I8
Electron Configuration[Rn] 5f10 7s2

Isotopes

NeutronsMassAbundanceRadioactive
251251.0795890Yes, 900.0 y
249249.07485390No
250250.07640620No
252252.0816270No
X
Es 99

Einsteinium

Albert Einstein, German physicist

Observed or predicted by A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) in 1952. Isolated in 1952.

Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons; kept secret for several years.

General Information

Mass252Amu
Meltingpoint1133.0K
Boilingpoint1269K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.3676eV
Radius-
Density8.84g/cm3
TypeMetal
SubtypeActinide
Groundlevel4Io15/2
Electron Configuration[Rn] 5f11 7s2

Isotopes

NeutronsMassAbundanceRadioactive
252252.082980Yes, 471.7 d
X
Fm 100

Fermium

Enrico Fermi, Italian physicist

Observed or predicted by A. Ghiorso et al. (Argonne Laboratory, Los Alamos Laboratory and University of California, Berkeley) in 1952.

Formed in the first thermonuclear explosion in November 1952, by irradiation of uranium with neutrons; kept secret for several years.

General Information

Mass257Amu
Meltingpoint1125K
Boilingpoint-K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.5eV
Radius-
Density9.7g/cm3
TypeMetal
SubtypeActinide
Groundlevel3H6
Electron Configuration[Rn] 5f12 7s2

Isotopes

NeutronsMassAbundanceRadioactive
257257.0951060Yes, 100.5 d
X
Md 101

Mendelevium

Dmitri Mendeleev, Russian chemist and inventor who proposed the periodic table

Observed or predicted by A. Ghiorso, G. Harvey, R. Choppin, S. G. Thompson and G. T. Seaborg (Berkeley Radiation Laboratory) in 1955.

Prepared by bombardment of einsteinium with helium.

General Information

Mass258Amu
Meltingpoint1100K
Boilingpoint-K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.58eV
Radius-
Density10.3g/cm3
TypeMetal
SubtypeActinide
Groundlevel2Fo7/2
Electron Configuration[Rn] 5f13 7s2

Isotopes

NeutronsMassAbundanceRadioactive
258258.0984310Yes, 51.5 d
256256.093890No
X
No 102

Nobelium

Alfred Nobel, Swedish chemist and engineer

Observed or predicted by E. D. Donets, V. A. Shchegolev and V. A. Ermakov (JINR in Dubna) in 1966.

First prepared by bombardment of uranium with neon atoms

General Information

Mass259Amu
Meltingpoint1100K
Boilingpoint-K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy6.65eV
Radius-
Density9.9g/cm3
TypeMetal
SubtypeActinide
Groundlevel1S0
Electron Configuration[Rn] 5f14 7s2

Isotopes

NeutronsMassAbundanceRadioactive
259259.101030Yes, 58.0 min
X
Lr 103

Lawrencium

Ernest O. Lawrence, American physicist

Observed or predicted by A. Ghiorso, T. Sikkeland, E. Larsh and M. Latimer (Berkeley Radiation Laboratory) in 1961.

First prepared by bombardment of californium with boron atoms.

General Information

Mass266Amu
Meltingpoint1900K
Boilingpoint-K
Electronegativity1.3
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy4.9eV
Radius-
Density15.6g/cm3
TypeMetal
SubtypeActinide
Groundlevel2Po1/2
Electron Configuration[Rn] 5f14 7s2 7p1

Isotopes

NeutronsMassAbundanceRadioactive
262262.109610Yes, 4.0 h
X
Rf 104

Rutherfordium

Ernest Rutherford, chemist and physicist from New Zealand

Observed or predicted by A. Ghiorso et al. (Berkeley Radiation Laboratory) and I. Zvara et al. (JINR in Dubna) in 1969.

Prepared by bombardment of californium with carbon atoms by Albert Ghiorso's team and by bombardment of plutonium with neon atoms by Zvara's team.

General Information

Mass267Amu
Meltingpoint2400K
Boilingpoint5800K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density23.2g/cm3
TypeMetal
SubtypeTransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
267--Yes, 2.5 h
261261.108770No
X
Db 105

Dubnium

Dubna, Russia, where the Joint Institute for Nuclear Research is located

Observed or predicted by A. Ghiorso et al. (Berkeley Radiation Laboratory) and V. A. Druin et al. (JINR in Dubna) in 1970.

Prepared by bombardment of californium with nitrogen atoms by Ghiorso's team and by bombardment of americium with neon atoms by Druin's team.

General Information

Mass268Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density29.3g/cm3
TypeMetal
SubtypeTransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
268--Yes, 29.0 h
270--Yes, 2.0 h
262262.114070No
X
Sg 106

Seaborgium

Glenn T. Seaborg, American chemist

Observed or predicted by A. Ghiorso et al. (Berkeley Radiation Laboratory) in 1974.

Prepared by bombardment of californium with oxygen atoms.

General Information

Mass269Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density35.0g/cm3
TypeMetal
SubtypeTransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
269--Yes, 5.0 min
271--Yes, 3.1 min
266266.1220No
X
Bh 107

Bohrium

Niels Bohr, Danish physicist

Observed or predicted by G.Münzenberg et al. (GSI in Darmstadt) in 1981.

Obtained by bombarding bismuth with chromium.

General Information

Mass270Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density37.1g/cm3
TypeMetal
SubtypeTransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
270--Yes, 3.8 min
271--Yes, 10.0 min
274--Yes, 60.0 s
272272.13830No
X
Hs 108

Hassium

New Latin Hassia, 'Hesse' (a state in Germany)

Observed or predicted by G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) in 1984.

Prepared by bombardment of lead with iron atoms

General Information

Mass270Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density40.7g/cm3
TypeMetal
SubtypeTransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
269--Yes, 16.0 s
270--Yes, 9.0 s
277277.15190Yes, 110.0 s
X
Mt 109

Meitnerium

Lise Meitner, Austrian physicist

Observed or predicted by G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt) in 1982.

Prepared by bombardment of bismuth with iron atoms.

General Information

Mass278Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density37.4g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
276276.15160Yes, 10.0 s
277--Yes, 9.0 s
278--Yes, 7.0 s
X
Ds 110

Darmstadtium

Darmstadt, Germany, where the element was first synthesised

Observed or predicted by S. Hofmann et al. (GSI in Darmstadt) in 1994.

Prepared by bombardment of lead with nickel

General Information

Mass281Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density34.8g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
280--Yes, 11.0 s
281281.16450Yes, 14.0 s
X
Rg 111

Roentgenium

Wilhelm Conrad Röntgen, German physicist

Observed or predicted by S. Hofmann et al. (GSI in Darmstadt) in 1994.

Prepared by bombardment of bismuth with nickel

General Information

Mass282Amu
Meltingpoint-K
Boilingpoint-K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density28.7g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
281--Yes, 24.0 s
282--Yes, 1.6 min
280280.16510No
X
Cn 112

Copernicium

Nicolaus Copernicus, Polish astronomer

Observed or predicted by S. Hofmann et al. (GSI in Darmstadt) in 1996.

Prepared by bombardment of lead with zinc.

General Information

Mass285Amu
Meltingpoint283K
Boilingpoint340K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density14.0g/cm3
TypeMetal
SubtypePosttransition Metal

Isotopes

NeutronsMassAbundanceRadioactive
285285.17710Yes, 32.0 s
X
Nh 113

Nihonium

Japanese Nihon, 'Japan' (where the element was first synthesised)

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) and K. Morita et al. (RIKEN in Wako, Japan) in 2003–2004.

Prepared by decay of moscovium by Oganessian's team and bombardment of bismuth with zinc by Morita's team

General Information

Mass286Amu
Meltingpoint700K
Boilingpoint1400K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density16g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
286--Yes, 7.0 s
X
Fl 114

Flerovium

Flerov Laboratory of Nuclear Reactions, part of JINR, where the element was synthesised; itself named after Georgy Flyorov, Russian physicist

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) in 1999.

Prepared by bombardment of plutonium with calcium

General Information

Mass289Amu
Meltingpoint-K
Boilingpoint210.0K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density14g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
289--Yes, 2.4 s
287287.18680No
X
Mc 115

Moscovium

Moscow Oblast, Russia, where the element was first synthesised

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) in 2003.

Prepared by bombardment of americium with calcium

General Information

Mass290Amu
Meltingpoint700K
Boilingpoint1400K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density13.5g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
288--Yes, 170.0 ms
289--Yes, 310.0 ms
290--Yes, 410.0 ms
X
Lv 116

Livermorium

Lawrence Livermore National Laboratory in Livermore, California, which collaborated with JINR on its synthesis

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) in 2000.

Prepared by bombardment of curium with calcium

General Information

Mass293Amu
Meltingpoint700K
Boilingpoint1100K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density12.9g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
293--Yes, 80.0 ms
291291.20110No
X
Ts 117

Tennessine

Tennessee, United States (where Oak Ridge National Laboratory is located)

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) in 2009.

Prepared by bombardment of berkelium with calcium

General Information

Mass294Amu
Meltingpoint700K
Boilingpoint883K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density7.2g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
294--Yes, 70.0 ms
X
Og 118

Oganesson

Yuri Oganessian, Russian physicist

Observed or predicted by Y. Oganessian et al. (JINR in Dubna) in 2002.

Prepared by bombardment of californium with calcium

General Information

Mass294Amu
Meltingpoint320K
Boilingpoint350K
Electronegativity-
Abundance (in earth)-mg/kg
Specific Heat-J/(g·K)
First Ionization Energy-eV
Radius-
Density5.0g/cm3
TypeUnknown
SubtypeUnknown

Isotopes

NeutronsMassAbundanceRadioactive
294--Yes, 1.15 ms