Ununoctium is the temporary IUPAC name for the transactinide element with the atomic number 118 and temporary element symbol Uuo. It is also known as eka-radon or element 118, and on the periodic table of the elements it is a p-block element and the last one of the 7th period. Ununoctium is currently the only synthetic member of group   18 . It has the highest atomic number and highest atomic mass of all the elements discovered so far.

The radioactive ununoctium atom is very unstable, due to its high mass, and since 2005, only three or possibly four atoms of the isotope   294 Uuo  have been detected. While this allowed for very little experimental characterization of its properties and possible compounds, theoretical calculations have resulted in many predictions, including some unexpected ones. For example, although ununoctium is a member of Group 18, it may possibly not be a noble gas, unlike all the other Group 18 elements. It was formerly thought to be a gas but is now predicted to be a solid under normal conditions due to relativistic effects.

Ununoctium

118Uuo

ununseptium ← ununoctium → ununennium

Ununoctium in the periodic table

Appearance

unknown

General properties

Name,symbol,number ununoctium, Uuo, 118

Pronunciation i / uː n . uː n ̍ ɒ k t i ə m / oon-oon-OK-tee-əm

Element category unknownbut probably a noble gas

Group, period,block 18 (noble gases), 7, p

Standard atomic weight [294]

Electron configuration [Rn] 5f14 6d10 7s2 7p6

(predicted) 2, 8, 18, 32, 32, 18, 8 (predicted)

Physical properties

Phase solid (predicted)

Liquid densityat m.p. 4.9–5.1 (predicted) g·cm−3

Boiling point (extrapolated) 350±30 K, 80±30 °C, 170±50 °F

Critical point (extrapolated) 439 K, 6.8MPa

Heat of fusion (extrapolated) 23.5kJ·mol−1

Heat of vaporization (extrapolated) 19.4 kJ·mol−1

Atomic properties

Oxidation states (predicted) −1, 0, +1, +2,+4, +6

Ionization energies 1st: 839.4 (predicted)  kJ·mol−1

2nd: 1563.1 (predicted) kJ·mol−1

Covalent radius (predicted) 157 pm

Miscellanea

CAS registry number 54144-19-3

History

Naming IUPAC systematic element name

Discovery Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory(2002)

Most stable isotopes

Main article: Isotopes of ununoctium

iso NA half-life

DM DE (MeV) DP

294Uuo syn ~0.89 ms

α 11.65 ± 0.06 290LvSF

HistoryThe discovery of the elements known to exist today is presented here in chronological order. The elements are listed generally in the order in which each was first defined as the pure element, as the exact date of discovery of most elements cannot be accurately defined.

Given is each element's name, atomic number, year of first report, name of the discoverer, and some notes related to the discovery.

Unrecorded discoveries

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Oldest

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Notes

29 Copper 9000 BC 6000 BC Middle East Anatolia

Copper was probably the first metal mined and crafted by man. 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 copper and bronze ages. Copper beads dating from 6000 BC have been found in Çatal Höyük, Anatolia.

82 Lead 7000 BC 3800 BC Near East Abydos, Egypt

It is believed that lead smelting began at least 9,000 years ago, and the oldest known artifact of lead is a

ZEleme

ntEarliest

use

Oldest

existing

sample

Discoverers

Place of

oldestsample

Notes

statuette found at the temple of Osiris on the site of Abydos dated circa 3800 BC.

79 GoldBefore 6000 BC

3000 BC Middle East Egypt

Archaeologists suggest that the first use of gold began with the first civilizations in the Middle East. It may have been the first metal used by humans. The oldest remaining gold jewelry is that in the tomb of Egyptian Queen Zer

47 SilverBefore 5000 BC

ca. 4000 BC

Asia Minor

Estimated to have been discovered shortly after copper and gold.

26 Iron Before 5000 BC

4000 BC Unknown; seeHistory of ferrous metallurgy

Egypt There is evidence that iron was known from before 5000 BC. The oldest known iron objects used by

ZEleme

ntEarliest

use

Oldest

existing

sample

Discoverers

Place of

oldestsample

Notes

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.

6 Carbon 3750 BC Egyptians and Sumerians

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. The first true chemical analyses were made in the 18th century, and in 1789

ZEleme

ntEarliest

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Oldest

existing

sample

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Place of

oldestsample

Notes

carbon was listed by Antoine Lavoisier as an element.

50 Tin 3500 BC 2000 BCUnknown; seeTin#History

First smelted in combination with copper around 3500 BC to produce bronze. The oldest artifacts date from around 2000 BC.

16 SulfurBefore 2000 BC

Chinese/Indians

First used at least 4,000 years ago. Recognized as an element by Antoine Lavoisier in 1777.

80 MercuryBefore 2000 BC

1500 BC Chinese/Indians Egypt

Known to ancient Chinese and Indians before 2000 BC, and found in Egyptian tombs dating from 1500 BC.

ZEleme

ntEarliest

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Oldest

existing

sample

Discoverers

Place of

oldestsample

Notes

30 ZincBefore 1000 BC

1000 BC Indian metallurgistsIndian subcontinent

Extracted as a metal since antiquity (before 1000 BC) by Indian metallurgists, but the true nature of this metal was not understood in ancient times. Identified as a unique metal by the metallurgistRasaratna Samuccaya in 800 and by the alchemist Paracelsus in 1526. Isolated byAndreas Sigismund Marggraf in 1746.

33 Arsenic2500 BC/1250 AD

Bronze age

A. Magnus

In use in the early bronze age; Albertus Magnus was the first European to isolate the element in 1250. In 1649, Johann Schröder published two ways of preparing elemental arsenic.

ZEleme

ntEarliest

use

Oldest

existing

sample

Discoverers

Place of

oldestsample

Notes

51 Antimony 3000 BCIn widespread use in Egypt and the Middle East.

24Chromium

Before 1 ADBefore 1 AD

Terracotta Army China

Found coating various weapons in China because of its high strength and corrosion resistance.

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

15 Phosphorus 1669 1669 H. Brand H. Brand

Prepared from urine, it was the first element to be chemically discovered.

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

27 Cobalt 1732 G. Brandt

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

78 Platinum 1735 1735 A. de Ulloa A. de Ulloa

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 byWilliam Brownrigg in 1750.

28 Nickel 1751 1751 F. Cronstedt F. Cronstedt

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

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

83 Bismuth 1753 C.F. GeoffroyDefinitively identified by Claude François Geoffroy in 1753.

12 Magnesium 1755 1808 J. Black H. Davy

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

1 Hydrogen 1766 1500 H. Cavendish Paracelsus

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 1793.

8 Oxygen 1771 1771 W. Scheele W. Scheele Obtained it by heating mercuric

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

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

7 Nitrogen 1772 1772 D. Rutherford D. Rutherford

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,

Z ElementObserved

or predicted

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(widely known

)

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and Lavoisier named it in 1775-6.

17 Chlorine 1774 1774 W. Scheele W. Scheele

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

25 Manganese 1774 1774 W. Scheele G. Gahn

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.

56 Barium 1772 1808 W. Scheele H. Davy

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

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

42 Molybdenum 1778 1781 W. Scheele J. Hjelm

Scheele recognised the metal as a constituent of molybdena.

52 Tellurium 1782F.-J.M. von Reichenstein

H. Klaproth

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

74 Tungsten 1781 1783 T. BergmanJ. and F. Elhuyar

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

38 Strontium 1787 1808 W. Cruikshank H. Davy Cruikshank and Adair Crawford in 1790 concluded that strontianite contained a new earth. It was eventually isolated electrochemically in

Z ElementObserved

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(widely known

)

ObserverFirst

isolatorNotes

1808 by Humphry Davy.

1789 A. Lavoisier

The first modern list of chemical elements –

containing, among others, 23 elements

of those known then. He also

redefined the term "element". Until then, no metals except mercury were considered

elements.

40 Zirconium 1789 1824 H. Klaproth J. BerzeliusKlaproth identified a new element in zirconia.

92 Uranium 1789 1841 H. Klaproth E.-M. Péligot Mistakenly identified a uranium oxide obtained from pitchblende as the element itself and named it after the recently discovered

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

planet Uranus.

22 Titanium 1791 1825 W. Gregor J. Berzelius

Gregor found an oxide of a new metal in ilmenite; Martin Heinrich 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.

39 Yttrium 1794 1840 J. Gadolin G. Mosander

Discovered in gadolinite, but Mosander showed later that its ore, yttria, contained more elements.

4 Beryllium 1798 1828 N. VauquelinF. Wöhler and A. Bussy

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

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

23 Vanadium 1801 1830 M. del RíoN.G.Sefström

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.

41 Niobium 1801 1864 C. HatchettW. Blomstrand

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

73 Tantalum 1802 G. Ekeberg Ekeberg found another element in minerals similar to columbite and in 1844, Heinrich Rose

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

proved that it was distinct from niobium.

46 Palladium 1803 1803 H. Wollaston H. Wollaston

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.

58 Cerium 1803 1839 H. Klaproth, J. Berzelius, and W. Hisinger

G. Mosander Berzelius and Hisinger discovered the element in ceria and named it after the newly discovered asteroid (then considered a

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

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.

76 Osmium 1803 1803 S. Tennant S. Tennant

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.

77 Iridium 1803 1803 S. Tennant S. Tennant Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

named osmium and iridium, and published the iridium results in 1804.

45 Rhodium 1804 1804 H. Wollaston H. Wollaston

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

19 Potassium 1807 1807 H. Davy H. DavyDavy discovered it by using electrolysis on potash.

11 Sodium 1807 1807 H. Davy H. Davy

Davy discovered it a few days after potassium, by using electrolysis on sodium hydroxide.

20 Calcium 1808 1808 H. Davy H. DavyDavy discovered the metal by electrolysis of quicklime.

5 Boron 1808 1808 L. Gay-Lussac andL.J.

H. Davy On June 21, 1808, Lussac and Thénard

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

Thénard

announced a new element in sedative salt, Davy announced the isolation of a new substance from boracic acid soon afterwards.

9 Fluorine 1810 1886 A.-M. Ampère H. Moissan

André-Marie Ampère predicted an element analogous to chlorine obtainable fromhydrofluoric acid, and between 1812 and 1886 many researchers tried to obtain this element. It was eventually isolated by Moissan.

53 Iodine 1811 1811 B. Courtois B. CourtoisCourtois discovered it in the ashes of seaweed.

3 Lithium 1817 1821 A. Arfwedson W. T. BrandeArfwedson discovered the alkali in petalite.

48 Cadmium 1817 1817 S. L Hermann, F. S. L All three found an

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

Stromeyer, and J.C.H. Roloff

Hermann, F. Stromeyer, and J.C.H. Roloff

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

34 Selenium 1817 1817J. Berzelius and G. Gahn

J. Berzelius and G. Gahn

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

14 Silicon 1824 1824 J. Berzelius J. Berzelius Humphry Davy thought in 1800 that silica was an element, not a compound, and in 1808 suggested the present name. In 1811 Louis-Joseph Gay-Lussac and Louis-Jacques Thénard probably prepared impure silicon, but Berzelius

Z ElementObserved

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(widely known

)

ObserverFirst

isolatorNotes

is credited with the discovery for obtaining the pure element in 1824.

13 Aluminium 1825 1825 H.C.Ørsted H.C.Ørsted

Antoine Lavoisier predicted in 1787 that alumine 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.

35 Bromine 1825 1825J. Balard and L. Gmelin

J. Balard and L. Gmelin

They both discovered the element in the autumn of 1825 and published the results the next year.

90 Thorium 1829 J. Berzelius Berzelius obtained the oxide of a new earth

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

in thorite.

57 Lanthanum 1838 G. Mosander

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.

68 Erbium 1842 G. Mosander

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

65 Terbium 1842 1842 G. Mosander G. Mosander

In 1842 Mosander split yttria into two more earths, erbia and terbia

44 Ruthenium 1807 1844 J. Sniadecki J. Sniadecki Sniadecki isolated the element in 1807, but his work was not ratified. Gottfried Wilhelm Osann thought that he

Z ElementObserved

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(widely known

)

ObserverFirst

isolatorNotes

found three new metals in Russian platinum samples, and in 1844 Karl Karlovich Klaus confirmed that there was a new element. Klaus is usually recognized as the discoverer of the element.

55 Caesium 1860 1882R. Bunsen and R. Kirchhoff

C. Setterberg

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 ofDürkheim mineral water. The pure metal was eventually isolated in 1882 by Setterberg.

37 Rubidium 1861 R. Bunsen and G. R. Kirchhoff

R. Bunsen Bunsen and Kirchhoff discovered it just a

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

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 Hervesy.

81 Thallium 1861 1862 W. Crookes C.-A. Lamy

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.

49 Indium 1863 1867F. Reich and T. Richter

T. Richter

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

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

2 Helium 1868 1895P. Janssen and N. Lockyer

W. Ramsay, T. Cleve, and N. Langlet

Janssen and Lockyer observed independently a yellow line in the solar spectrum that did not match any other element.

Years later, Ramsay, Cleve, and Langlet observed independently the element trapped in cleveite about the same time.

1869 D. I. Mendeleev

Mendeleev arranges the 63 elements

known at that time into the first modern

periodic table and correctly predicts

several others.

31 Gallium 1875 P. E. L. de Boisbaudran

P. E. L. de Boisbaudran

Boisbaudran observed on a pyrenea blende sample some emission lines corresponding to the eka-aluminium that was predicted by

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

Mendeleev in 1871 and subsequently isolated the element by electrolysis.

70 Ytterbium 1878 1907 J.C.G. de Marignac G. Urbain

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

67 Holmium 1878 M. Delafontaine

Delafontaine found it in samarskite and next year, Per Teodor Cleve split Marignac's erbia into erbia proper and two new elements, thulium and holmium.

69 Thulium 1879 1879 T. Cleve T. Cleve

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

21 Scandium 1879 1879 F. Nilson F. Nilson Nilson split Marignac's ytterbia into pure ytterbia and a new element that matched 1871 Mendeleev's

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

predicted eka-boron.

62 Samarium 1879 1879P.E.L. de Boisbaudran

P.E.L. de Boisbaudran

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

64 Gadolinium 1880 1886J. C. G. de Marignac

F. L. de Boisbaudran

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

59Praseodymium

1885 A. von Welsbach

Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium.

60 Neodymium 1885 A. von Welsbach

Von Welsbach discovered two new distinct elements in ceria: praseodymium and neodymium.

66 Dysprosium 1886P.E.L. de Boisbaudran

De Boisbaudran found a new earth in erbia.

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

32 Germanium 1886 A. Winkler

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

18 Argon 1894 1894Lord Rayleigh and W. Ramsay

Lord Rayleigh and W. Ramsay

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.

36 Krypton 1898 1898W. Ramsay and W. Travers

W. Ramsay and W. Travers

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

10 Neon 1898 1898W. Ramsay and W. Travers

W. Ramsay and W. Travers

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

54 Xenon 1898 1898 W. Ramsay and W. Travers

W. Ramsay and W.

On July 12, 1898 Ramsay separated a

Z ElementObserved

or predicted

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)

ObserverFirst

isolatorNotes

Travers

third noble gas within three weeks, from liquid argon by difference in boiling point.

84 Polonium 1898 1902 P. and M. CurieW. Marckwald

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.

88 Radium 1898 1902 P. and M. Curie M. Curie

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

86 Radon 1898 1910 E. Dorn

W. Ramsay and R. Whytlaw-Gray

Dorn discovered a radioactive gas resulting from the radioactive decay of radium, isolated later by Ramsay and Gray.

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

89 Actinium 1899 1899 A.-L. DebierneA.-L. Debierne

Debierne obtained from pitchblende a substance that had properties similar to those of thorium.

63 Europium 1896 1901 E.-A. DemarçayE.-A. Demarçay

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

71 Lutetium 1906 1906G. Urbain and C.A. von Welsbach

G. Urbain and C.A. von Welsbach

Urbain and von Welsbach proved independently that the old ytterbium also contained a new element

75 Rhenium 1908[contradiction] 1908 M. Ogawa M. Ogawa Ogawa found it in thorianite but assigned it as element 43 instead of 75 and named it nipponium. In 1922 Walter Noddack, Ida Eva Tacke and Otto Berg announced its

Z ElementObserved

or predicted

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)

ObserverFirst

isolatorNotes

separation from gadolinite and gave it the present name.

72 Hafnium 1911 1922G. Urbain and V. Vernadsky

D. Coster and G. von Hevesy

Urbain claimed to have found the element in rare-earth residues, while Vernadsky independently found it in orthite. Neither claim was confirmed due to World War I. After the war, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon. Hafnium was the next to last element with stable isotopes to be discovered.

91 Protactinium 1913 O.H.Göhring and K. Fajans

The two obtained the first isotope of this element that had been predicted by Mendeleev in 1871 as a member of the

Z ElementObserved

or predicted

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)

ObserverFirst

isolatorNotes

natural decay of 238U.[107] Originally isolated in 1900 by William Crookes.

43 Technetium 1937 1937C. Perrier and E. Segrè

C. Perrier & E.Segrè

The two discovered a new element in a molybdenum sample that was used in acyclotron, the first synthetic element to be discovered. It had been predicted by Mendeleev in 1871 as eka-manganese.

87 Francium 1939 M. Perey Perey discovered it as a decay product of 227Ac.[111] Francium is the last element to be discovered in nature, rather than synthesized in the lab, although some of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine) were eventually found in trace amounts in

Z ElementObserved

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)

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nature as well.

85 Astatine 1940R. Corson, R. Mackenzie and E. Segrè

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

93 Neptunium 1940E.M. McMillan and H. Abelson

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

94 Plutonium 1940–1941

Glenn T. Seaborg,Arthur C. Wahl, W. Kennedy and E.M. McMillan

Prepared by bombardment of uranium with deuterons.

95 Americium 1944

G. T. Seaborg, A. James, O. Morganand A. Ghiorso

Prepared by irradiating plutonium with neutrons during the Manhattan Project.

96 Curium 1944 G. T. Seaborg, R. A. James and A.

Prepared by bombarding plutonium

Z ElementObserved

or predicted

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(widely known

)

ObserverFirst

isolatorNotes

Ghiorsowith alpha particles during the Manhattan Project

61 Promethium 1942 1945S. Wu, E.G. Segrèand A. Bethe

Charles D. Coryell, Jacob A. Marinsky,Lawrence E. Glendenin, andHarold G. Richter

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.

97 Berkelium 1949

G. Thompson, A. Ghiorso and G. T. Seaborg (University of

California, Berkeley)

Created by bombardment of americium with alpha particles.

98 Californium 1950

S. G. Thompson, K. Street,Jr., A. Ghiorso and G. T. Seaborg(University of

California, Berkeley)

Bombardment of curium with alpha particles.

99 Einsteinium 1952 1952 A. Ghiorso et al.

(Argonne Laboratory,Los

Alamos Laboratoryand

Formed in the first thermonuclear explosion in

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

University of California,

Berkeley)

November 1952, by irradiation of uranium with neutrons; kept secret for several years.

100 Fermium 1952

A. Ghiorso et al.

(Argonne Laboratory, Los

Alamos Laboratory and

University of California,

Berkeley)

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

101 Mendelevium 1955

A. Ghiorso, G. Harvey, R. Choppin, S. G. Thompson and G. T. Seaborg

Prepared by bombardment of einsteinium with helium.

102 Nobelium 1958

A. Ghiorso, T. Sikkeland, R. Waltonand G. T. Seaborg

First prepared by bombardment of curium with carbon atoms.

103 Lawrencium 1961

A. Ghiorso, T. Sikkeland, E. Larshand M. Latimer

First prepared by bombardment of californium with boron atoms

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

104Rutherfordium

1968

A. Ghiorso, M. Nurmia, J. Harris, K. Eskola and P. Eskola

Prepared by bombardment of californium with carbon atoms.

105 Dubnium 1970

A. Ghiorso, M. Nurmia, K. Eskola, J. Harris and P. Eskola

Prepared by bombardment of californium with nitrogen atoms.

106 Seaborgium 1974

A. Ghiorso, J. Nitschke, J. Alonso,C. Alonso, M. Nurmia, G. T. Seaborg, K. Hulet and W. Lougheed

Prepared by collisions of californium-249 with oxygen atoms.

107 Bohrium 1981G.Münzenberg et al.(GSI in Darmstadt)

Obtained by bombarding bismuth with chromium.

109 Meitnerium 1982G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt)

Prepared by bombardment of bismuth with iron atoms.

108 Hassium 1984G. Münzenberg, P. Armbruster et al. (GSI in Darmstadt)

Prepared by bombardment of lead with iron atoms

Z ElementObserved

or predicted

Isolated

(widely known

)

ObserverFirst

isolatorNotes

110Darmstadtium

1994S. Hofmann et al. (GSI in Darmstadt)

Prepared by bombardment of lead with nickel.

111 Roentgenium 1994S. Hofmann et al. (GSI in Darmstadt)

Prepared by bombardment of bismuth with nickel.

112 Copernicium 1996S. Hofmann et al. (GSI in Darmstadt)

Prepared by bombardment of lead with zinc.

114 Flerovium 1999Y. Oganessian et al.(JINR in Dubna)

Prepared by bombardment of plutonium with calcium

116 Livermorium 2000Y.Oganessian et al.

(JINR in Dubna)

Prepared by bombardment of curium with calcium

Unconfirmed discoveries

Z Name Discoveryyear Discoverer Notes

118 Ununoctium2002

Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

Prepared by bombardment of californium with calcium

113 Ununtrium 2003

Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

Alpha decay of ununpentium

115 Ununpentium 2003

Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

Prepared by bombardment of americium with calcium[

117 Ununseptium 2010

Joint Institute for Nuclear Research in Dubna and Lawrence Livermore National Laboratory

Prepared by bombardment of berkelium with calcium

Graphics

Development in discovery

Unsuccessful synthesis attempts

In late 1998, Polish physicist Robert Smolańczuk published calculations on the fusion of atomic nuclei towards the synthesis ofsuperheavy atoms, including ununoctium. His calculations suggested that it might be possible to make ununoctium by fusing leadwith krypton under carefully controlled conditions.

In 1999, researchers at Lawrence Berkeley National Laboratory made use of these predictions and announced the discovery oflivermorium and

ununoctium, in a paper published in Physical Review Letters, and very soon after the results were reported inScience. The researchers reported to have performed the reaction

86   208  293 Kr + Pb → Uuo + n36 82 118

The following year, they published a retraction after researchers at other laboratories were unable to duplicate the results and the Berkeley lab itself was unable to duplicate them as well. In June 2002, the director of the lab announced that the original claim of the discovery of these two elements had been based on data fabricated by principal author Victor Ninov.Discovery reportsThe first decay of atoms of ununoctium was observed at the Joint Institute for Nuclear Research (JINR) by Yuri Oganessian and his group in Dubna, Russia, in 2002. On October 9, 2006, researchers from JINR and Lawrence Livermore National Laboratory of California, US, working at the JINR in Dubna, announced that they had indirectly detected a total of three (possibly four) nuclei of ununoctium-294 (one or two in 2002 and two more in 2005) produced via collisions of californium-249 atoms and calcium-48 ions.

249 48 294

Cf + Ca → Uuo + 3n

98 20 118

In 2011, IUPAC evaluated the 2006 results of the Dubna-Livermore collaboration and concluded: "The three events reported for the Z = 118 isotope have very good internal redundancy but with no anchor to known nuclei do not satisfy the criteria for discovery".

Because of the very small fusion reaction probability (the fusion cross section is ~0.3–0.6 pb or(3–6)×10−41 m2) the experiment took four months and involved a beam dose of 4×1019calcium ions that had to be shot at the californium target to produce the first recorded event believed to be the synthesis of ununoctium. Nevertheless, researchers are highly confident that the results are not a false positive, since the chance that the detections were random events was estimated to be less than one part in 100000.

In the experiments, the alpha-decay of three atoms of ununoctium was observed. A fourth decay by direct spontaneous fission was also proposed. A half-life of0.89 ms Was calculated:

294 Uuo decays into 290 Lv by alpha decay. Since there were only three nuclei, the half-life derived from observed lifetimes has a large uncertainty: 0.89+1.07−0.31 ms.

294 290 4

Uuo → Lv + He

118 116 2

The identification of the 294Uuo nuclei was verified by separately creating the putative daughter nucleus 290Lv directly by means of a bombardment of 245Cm with 48Ca ions,

245 48 290

Cm + Ca → Lv + 3n

96 20 116

and checking that the 290Lv decay matched the decay chain of the 294Uuo nuclei. The daughter nucleus 290Lv is very unstable, decaying with a lifetime of 14 milliseconds into 286Fl, which may experience either spontaneous fission or alpha decay into 282Cn, which will undergo spontaneous fission.

In a quantum-tunneling model, the alpha decay half-life of 294 Uuo was predicted to be 0.66+0.23 −0.18 ms with the experimental Q-value

published in 2004. Calculation with theoretical Q-values from the macroscopic-microscopic model of Muntian–Hofman–Patyk–Sobiczewski gives somewhat low but comparable results.

Ununoctium-294 nuclear.svg

Radioactive decay pathway of the isotope ununoctium-294. The decay energy and average half-life is given for the parent isotopeand each daughter isotope. The fraction of atoms undergoingspontaneous fission (SF) is given in green.

NamingUntil the 1960s ununoctium was known as eka-emanation (emanation is the old name for radon). In 1979 the IUPAC published recommendations according to which the element was to be called ununoctium,  a systematic element name, as a placeholder until the discovery of the element is confirmed and the IUPAC decides on a name.

Before the retraction in 2002, the researchers from Berkeley had intended to name the element ghiorsium (Gh), after Albert Ghiorso (a leading member of the research team).

The Russian discoverers reported their synthesis in 2006. In 2007, the head of the Russian institute stated the team were considering two names for the new element: flyorium, in honor of Georgy Flyorov, the founder of the research laboratory in Dubna; and moskovium, in recognition of the Moscow Oblast where Dubna is located. He also stated that although the element was discovered as an American collaboration, who provided the californium target, the element should rightly be named in honor of Russia since the Flerov Laboratory of Nuclear Reactions at JINR was the only facility in the world which could achieve this result. These names were later proposed for element 114(flerovium) and element 116 (moscovium).

However, the final name proposed for element 116 was instead livermorium.

No name has yet been officially suggested for the element as no claims for discovery have yet been accepted by the IUPAC. According to current guidelines from IUPAC, the ultimate name for all new elements should end in "-ium", which means the name for ununoctium will almost certainly end in "-ium", not "-on", even if ununoctium turns out to be anoble gas, which traditionally have names ending in "-on" (with the exception of helium, which was not known to be a noble gas when it was discovered).

CharacteristicsNucleus stability and isotopes

The stability of nuclei decreases greatly with the increase in atomic number after plutonium, the heaviest primordial element, so that all isotopes with an atomic number above 101 decay radioactively with a half-life under a day, with an exception of dubnium-268. No elements with atomic numbers above 82 (after lead) have stable isotopes. Nevertheless, because of reasons not very well understood yet, there is a slight increased nuclear stability around atomic numbers 110–114, which leads to the appearance of what is known in nuclear physics as the "island of stability". This concept, proposed by University of California professor Glenn Seaborg, explains why super heavy elements last longer than predicted. Ununoctium is radioactive and has a half-life that appears to be less than a millisecond. Nonetheless, this is still longer than some predicted values, thus giving further support to the idea of this "island of stability".

Calculations using a quantum-tunneling model predict the existence of several neutron-rich isotopes of ununoctium with alpha-decay half-lives close to 1 ms.

Theoretical calculations done on the synthetic pathways for, and the half-life of, other isotopes have shown that some could be slightly more stable than the synthesized the synthesized isotope294Uuo, most likely 293Uuo, 295Uuo, 296Uuo, 297Uuo, 298Uuo, 300Uuo and 302Uuo. Of these, 297Uuo might provide the best chances for obtaining longer-lived nuclei, and thus might become the focus of future work with this element. Some isotopes with many more neutrons, such as some located around 313Uuo could also provide longer-lived nucleiCalculated atomic and physical properties

Ununoctium is a member of group 18, the zero-valence elements. The members of this group are usually inert to most common chemical reactions (for example, combustion) because the outer valence shell is completely filled with eight electrons. This produces a stable, minimum energy configuration in which the outer electrons are tightly bound. It is thought that similarly, ununoctium has a closed outer valence shell in which its valence electrons are arranged in a 7s27p6 configuration.

Consequently, some expect ununoctium to have similar physical and chemical properties to other members of its group, most closely resembling the noble gas above it in the periodic table, radon. Following the periodic trend, ununoctium would be expected to be slightly more reactive than radon. However, theoretical calculations have shown that it could be quite reactive, so that it probably cannot be considered a noble gas. In addition to being far more reactive than radon, ununoctium may be even more reactive than elements flerovium and copernicium. The reason for the apparent enhancement of the chemical activity of ununoctium relative to radon is an energetic destabilization and a radial expansion of the last occupied 7p-subshell. More precisely, considerable spin–orbit interactions between the 7p electrons with the inert 7s2 electrons, effectively lead to a second valence shell closing at flerovium, and a significant decrease in stabilization of the closed shell of element 118. It has also been calculated that ununoctium, unlike other noble gases, binds an electron with release of energy—or in other words, it exhibits positive electron affinity.

Ununoctium is expected to have by far the broadest polarizability of all elements before it in the periodic table, and almost twofold of radon. [1] By extrapolating from the other noble gases, it is expected that ununoctium has a boiling point between 320 and 380 K. This is very different from the previously estimated values of 263 K or 247 K. Even given the large uncertainties of the calculations, it seems highly unlikely that ununoctium would be a gas under standard conditions, and as the liquid range of the other gases is very narrow, between 2 and 9 kelvins, this element should be solid at standard conditions. If ununoctium forms a gas under standard conditions nevertheless, it would be one of the densest gaseous substances at standard conditions (even if it is monatomic like the other noble gases).

Because of its tremendous polarizability, ununoctium is expected to have an anomalously low ionization energy (similar to that of lead which is 70% of that of radonand significantly smaller than that of flerovium) and a standard state con densed phasePredicted compounds

No compounds of ununoctium have been synthesized yet, but calculations on theoretical compounds have been performed since 1964. It is expected that if the ionization energy of the element is high enough, it will be difficult to oxidize and therefore, the most common oxidation state will be 0 (as for other noble gases);[  nevertheless, this appears not to be the case.

Calculations on the diatomic molecule Uuo2 showed a bonding interaction roughly equivalent to that calculated for Hg2, and a dissociation energy of 6 kJ/mol, roughly 4 times of that of Rn2. But most strikingly, it was calculated to have a bond length shorter than in Rn2 by 0.16 Å, which would be indicative of a significant bonding interaction. On the other hand, the compound UuoH+ exhibits a dissociation energy (in other words proton affinity of Uuo) that is smaller than that of RnH+.

The bonding between ununoctium and hydrogen in UuoH is predicted to be very limp and can be regarded as a pure van der Waals interaction rather than a true chemical bond. On the other hand, with highly electronegative elements, ununoctium seems to form more stable compounds than for example copernicium or flerovium. The stable oxidation states +2 and +4 have been predicted to exist in the fluorides UuoF2 and UuoF4. The +6 state would be less stable due to the strong binding of the

7p1/2 subshell. This is a result of the same spin-orbit interactions that make ununoctium unusually reactive.

For example, it was shown that the reaction of ununoctium with F2 to form the compound UuoF2 would release an energy of 106 kcal/mol of which about 46 kcal/mol come from these interactions. 

For comparison, the spin-orbit interaction for the similar molecule RnF2 is about 10 kcal/mol out of a formation energy of 49 kcal/mol. The same interaction stabilizes the tetrahedral Td  configuration  for UuoF4, as distinct from the square planar D4h  one  of XeF4 which RnF4 is also expected to have. The Uuo–F bond will most probably be ionic rather than covalent, rendering the UuoFncompounds non-volatile. UuoF2 is predicted to be partially ionic due to ununoctium's high electropositivity. Unlike the other noble gases (except possibly xenon), ununoctium was predicted to be sufficiently electropositive to form a Uuo–Cl bond with chlorine.

XeF4 has a square planar configuration.

UuoF4 is predicted to have a tetrahedral configuration.

Experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

Table: basic information about and classifications of ununoctium.

Name : Ununoctium Symbol : Uuo Atomic number : 118 Atomic weight : [ 294 ] Standard state : presumably a gas at

298 K CAS Registry ID : 54144-19-3

Group in periodic table : 18 Group name : Noble gas Period in periodic table : 7 Block in periodic table : p-block Colour : unknown, but probably a

colourless gas Classification : Non-metallic

Ununoctium: historical informationUnunoctium was discovered by (not yet confirmed) at 2002 (not yet confirmed. A claim in 1999 was retracted later) in (not yet confirmed). Origin of name: temporary systematic IUPAC nomenclature.

Experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

The 2002 experiment involved firing a beam of 4820Ca at 249

98Cf. The experiment took 4 months and involved a beam of 2.5 x 1019 calcium ions to produce the single event believed to be the synthesis of element 118 (ununoctium) as the249

118Uuo isotope. Three neutrons are released during this process

24998Cf + 48

20Ca → 294118Uuo + 31n

This research was reported at an IUPAC conference in China (Yu. Ts. Oganessian, "Synthesis and decay properties of superheavy elements", Pure Appl. Chem., 2006, 78, 889-904.) in August 2006 and then more recently in Phys Rev C [Yu. Ts. Oganessian, V. K. Utyonkov, Yu. V. Lobanov, F. Sh. Abdullin, A. N. Polyakov, R. N. Sagaidak, I. V. Shirokovsky, Yu. S. Tsyganov, A. A. Voinov, G. G. Gulbekian, S. L. Bogomolov, B. N. Gikal, A. N. Mezentsev, S. Iliev, V. G. Subbotin, A. M. Sukhov, K. Subotic, V. I. Zagrebaev, G. K. Vostokin, M. G. Itkis, K. J. Moody, J. B. Patin, D. A. Shaughnessy, M. A. Stoyer, N. J. Stoyer, P. A. Wilk, J. M. Kenneally, J. H. Landrum, J. F. Wild, and R. W. Lougheed, "Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions", Phys. Rev. C , 2006, 74 , 044602 ].

Earlier, a team of Berkeley Lab scientists announced in 1999 the observation of what appeared to be element 118 but retracted the claim after several confirmation experiments failed to reproduce the results. Please see this page for more details. In this work it was claimed that elements 118 and 116 were formed by accelerating a beam of krypton-86 (86

36Kr) ions to an energy of 449 million electron volts and directing the beam onto targets of lead-208 (208

82Pb). After 11 days work, just three atoms of the

new element were identified. The production rates for element 118 are approximately one in every 1012 interactions.

20882Pb + 86

36Kr → 293118Uuo + 1n

These experiments were carried out following calculations by Robert Smolanczuk (Soltan Institute for Nuclear Studies, Poland) on the fusion of atomic nucleii. His calculations suggested that it might be possible to make element 118 by fusing lead with krypton under carefully controlled conditions.

Ununoctium: physical properties

Melting point: no data K

Boiling point: no data K

Density of solid: 5700 (predicted, other prediction 5000) kg m-3

 Read more   »   »

Ununoctium: orbital properties

Ground state electron configuration :  [Rn].5f14.6d10.7s2.7p6 (a guess based upon that of radon)

Shell structure :  2.8.18.32.32.18.8 Term symbol :   1S0 (a guess based upon guessed electronic structure)

Pauling electronegativity: no data (Pauling units)

  First ionisation energy : no data kJ mol-1

  Second ionisation energy : no data kJ mol-1

 Read more   »   »

Isolation

Isolation: experiments conducted at Dubna in Russia at the Flerov Laboratory of Nuclear Reactions (by workers from the Joint Institute for Nuclear Research in Russia and the Lawrence Livermore National Laboratory in the USA) indicate that element 118 (ununoctium, Uuo) was produced. Not too much though, one atom in the spring of 2002 and two more in 2005.

The 2002 experiment involved firing a beam of 4820Ca at 249

98Cf. The experiment took 4 months and involved a beam of 2.5 x 1019 calcium ions to produce the single event believed to be the synthesis of element 118 (ununoctium) as the294

118Uuo isotope. Three neutrons are released during this process.

24998Cf + 48

20Ca → 294118Uuo + 31n

This ununoctium isotope then loses three alpha particles in rapid succesion:

294118Uuo → 290

116Lv + 42He (1.29 milliseconds)

290116Lv → 286

114Fl + 42He (14.4 milliseconds)

286114Fl → 282

112Uub + 42He (230 milliseconds)

The 282112Cn species then undergoes spontaneous fission (denoted SF) to other species.

An important part of this work was additional work synthesising isotopes of element 116 through irradiation of 245Cm (as opposed to 249Cm referred to above).

24598Cf + 48

20Ca → 290116Lv + 31n

Analysis of this reaction very clearly indicates that 290116Lv is indeed a decomposition

product of 294118Uuo. This research was reported at an IUPAC conference in China (Yu.

Ts. Oganessian, "Synthesis and decay properties of superheavy elements", Pure Appl. Chem., 2006, 78, 889-904.) in August 2006 and then more recently in Phys Rev C [Yu. Ts. Oganessian, V. K. Utyonkov, Yu. V. Lobanov, F. Sh. Abdullin, A. N. Polyakov, R. N. Sagaidak, I. V. Shirokovsky, Yu. S. Tsyganov, A. A. Voinov, G. G. Gulbekian, S. L. Bogomolov, B. N. Gikal, A. N. Mezentsev, S. Iliev, V. G. Subbotin, A. M. Sukhov, K. Subotic, V. I. Zagrebaev, G. K. Vostokin, M. G. Itkis, K. J. Moody, J. B. Patin, D. A. Shaughnessy, M. A. Stoyer, N. J. Stoyer, P. A. Wilk, J. M. Kenneally, J. H. Landrum, J. F. Wild, and R. W. Lougheed, "Synthesis of the isotopes of elements 118 and 116 in the 249Cf and245Cm+48Ca fusion reactions", Phys. Rev. C , 2006,   74 , 044602 ].

Earlier, a team of Berkeley Lab scientists announced in 1999 the observation of what appeared to be element 118 but retracted the claim after several confirmation experiments failed to reproduce the results. This means that the following apparently is wrong. Please see this page for more details. In this work it was claimed that elements 118 and 116 were formed by accelerating a beam of krypton-86 (86

36Kr) ions to an energy of 449 million electron volts and directing the beam onto targets of lead-208 (208

82Pb). After 11 days work, just three atoms of the new element were identified. The production rates for element 118 are approximately one in every 1012 interactions.

20882Pb + 86

36Kr → 293118Uuo + 1n

The element 118 nucleus was said to decay less than a millisecond after its formation by emitting an α-particle resulting in an isotope of element 116 (mass number 289, containing 116 protons and 173 neutrons). This isotope of element 116 undergoes further α-decay processes to an isotope of element 114 and so on down to at least element 106 (seaborgium).

293118Uuo → 289

116Lv + 42He (0.12 milliseconds)

289116Lv → 285

114Fl + 42He (0.60 milliseconds)

285114Fl → 281

112Cn + 42He (0.58 milliseconds)

281112Cn → 277Ds + 4

2He (0.89 milliseconds)

277Ds → 273108Hs + 4

2He (3 milliseconds)

273108Hs → 269

106Sg + 42He (1200 milliseconds)

  Ununoctium   Ununoctium

  Ununoctium   Ununoctium

  Ununoctio   Ununoctio

  Ununoctium   Ununoctio

Ununoctiumo Essential data : names, symbol, atomic number, and atomic

weight; block, period, and group in periodic table; description; standard state; registry number; and isolation

o History : meaning of name; discovery; and history of the elemento Uses o Find a property

Ununoctium around uso Geology : Abundance of elements in the universe; the sun;

meteorites; Earth's crust; oceans; and streamso Biology : Abundance in humans; biological role; and health

hazards) Search Chemistry Webo

Chemistry and compoundso Compounds : halides, oxides, sulfides, hydrides, and complexes;

lattice energies; and reduction potentials

o Reactions of ununoctium : reactions of ununoctium with air; water; halogens; acids; and bases

o Electronegativities : Pauling; Sanderson; Allred Rochow; Mulliken-Jaffe; and Allen

o Bond enthalpies  of diatomic specieso Lattice energies Element propertieso Physics properties : Boiling point; melting point; density; molar

volume; thermal conductivity; and electrical resistivity; bulk modulus; critical temperature; superconductivity temperature; hardness (mineralogical, Brinell, and Vickers); linear expansion coefficient; Poisson's ratio; reflectivity; refractive index; rigidity modulus; Young's modulus; velocity of sound

o Crystal structure o Thermochemistry : enthalpies of atomization, fusion, and

vaporization; thermodynamic propertieso Pictures Atom propertieso Electron shell properties : Electronic configuration; term

symbol; electron affinity; ionization energies; and atomic spectrao Atom sizes : atomic radius; Shannon and Pauling ionic radii;

covalent radius; metallic radius; element bond length; and Van der Waals radius

o Atomic orbital properties : effective nuclear charge; electron binding energies; and valence orbital radii maxima

Nuclear propertieso Isotopes : isotope abundances; radioactive isotopes; isotope

masses; nuclear spins; and nuclear magnetic momento NMR properties : frequencies; isotopes; magnetogyric ratios;

quadrupole moments; receptivities; and relative sensitivities

Ununoctium UnunoctiumThe Ununoctium was discovered by V. Ninov and many of collaborates that was A.Ghiorso, W.J. Siatecki,C.A. Laue, J.B. Patin, D.A. Shaughnessy, D.A. Strellis, and P.A.Wilk in the year of 1996 in Berkeley, California and the university of the state of Oregon inUSA.

Basic Information: Name: Ununoctium.Symbol: UuoAtomic Number: 118Atomic Mass: 293The origin: Temporary name proposed by the IUPAC.From Latin: Un(one)un (one) octium (eight) as the element 118 of the periodic table.Characteristics and the main properties of Ununoctium.Characteristics:1. Scientists at the Joint Institute for Nuclear Research in Russia showed that in the element 118 has been produced an atom in the spring in 2002 and two more in 2005.2. Ununoctium is a radioactive element and has a half life that seems to be less than a millisecond.3. Colour: unknown, but probably a colourless gas.4. Classification: Non-metallic.5. Availability: Not commercially available.6. Group in the periodic table was 8.7. The Ununoctium structure was crystalProperties:1. The atomic number of Ununoctium was 1182. The symbol of Ununoctium was Uuo.3. The atomic weight was 293.4. Ununoctium is a member of group 18. Members of this group tend to be material inert to mostcommon chemical reactions (for example the combustion), as the outer valence shell is completelyfilled with eight electrons. This produces a stable form, minimum energy in which the configurationthe outer electrons are closely linked.The electron Configuration of Ununoctium:1s2 2s2 2p6 3s2 3p6 4s2 3d1 4p6 5s2 4d1 5p6 6s2 4f4 5d1 6p6 7s2 5f4 6d1 7p6Uses:Since only three atoms of Ununoctium have ever been produced, it currently has no uses outside of  basic scientific research. It would constitute a radiation hazard if enough were ever assembled inone place.Ionization Energy (1st) kJ mol-1Ionization Energy (2nd) kJ mol-1 IonizationEnergy (3rd) kJ mol-1