352 | The History and Use of Our Earth’s Chemical Elements Examples฀of฀Compounds

352 | The History and Use of Our Earth’s Chemical Elements Examples฀of฀Compounds

None have been reported. Hazards None, beyond minor risks from radiation because only a few atoms of darmstadtium are

produced at a time, and all of its isotopes exist for only a small fraction of second. RÖENTGENIUM฀(UNUNUNIUM) SYMBOL:฀Rg฀and฀Uuu฀ PERIOD:฀7฀ SERIES฀NAME:฀Transactinide฀ ATOMIC฀NO:฀111

ATOMIC฀MASS:฀˜280฀amu฀ VALENCE:฀Unknown฀ OXIDATION฀STATE:฀Unknown ORIGIN฀OF฀NAME:฀Named฀in฀honor฀of฀the฀scientist฀Wilhelm฀Konrad฀Röentgen. ISOTOPES:฀There฀are฀three฀isotopes฀of฀Uuu฀(Röentgenium).฀They฀are฀Rg-272฀(half-life฀of฀

1.5฀milliseconds),฀Rg-279฀(half-life฀of฀170฀milliseconds),฀and฀Rg฀280฀(half-life฀of฀3.2฀ seconds),฀the฀latter฀of฀which฀is฀röentgenium’s฀most฀stable฀isotope.฀All฀of฀its฀isotopes฀are฀ synthetic฀and฀unstable.

ELECTRON฀CONFIGURATION ฀ Energy฀Levels/Shells/Electrons฀ Orbitals/Electrons

s2,฀p6

฀ 3-M฀=฀18฀

s2,฀p6,฀d10

฀ 4-N฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 5-O฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 6-P฀=฀17฀

s2,฀p6,฀d9

฀ 7-Q฀=฀2฀

s2

Properties฀and฀Characteristics Not much is known about element 111, but it is assumed that it is a solid metal that has

some of the properties of its homologues, gold and silver, located just above it in group 1 (IB) in the periodic table. The reaction that produces unununium is as follows:

Bi-209 + Ni-64 + neutrons = Uuu-272 + alpha decay particles. Only a few atoms of Rg-272 have been produced. Its most stable isotope is Rg-280, with a half-life of 3.6 seconds.

History Shortly after element 110 was discovered in 1994, the team led by Peter Armbruster and

Sigurd Hofmann at the Institute for Heavy Ion Research at Darmstadt, Germany, discovered element 111 using their SHIP detection apparatus. One might speculate that the ancient alchemists would be impressed by the production of element 111 by the transmutation of two

353 different elements. Very high-energy nickel ions were used to bombard bismuth atoms. This

Guide to the Elements |

caused the nuclei of the two atoms to fuse together by the process off “cold fusion,” producing unununium. Gold, located in period 6, group 11, just above unununium, is its homologue (element with some similar characteristics). The alchemist’s ancient dream would be to pro- duce gold by a similar process. Unfortunately, only three atoms of 111 Rg were produced after an 18-day experiment, and their half-lives was extremely short.

Common฀Uses None, except for research purposes.

Examples฀of฀Compounds None are known at this time.

Hazards Unununium (röentgenium) is not a public radiation hazard given that only a few atoms

have been produced synthetically in nuclear laboratories and they do not exist over long peri- ods of time.

UNUNBIUM฀( 112 UUB-285) SYMBOL:฀Uub฀ PERIOD:฀7฀ SERIES฀NAME:฀Transactinide฀ ATOMIC฀NO:฀112

ATOMIC฀MASS:฀˜285฀amu฀ VALENCE:฀Unknown฀ OXIDATION฀STATE:฀Unknown฀ NATU- RAL฀STATE:฀Assumed฀to฀be฀liquid฀metal ORIGIN฀OF฀NAME:฀IUPAC฀transition฀name,฀“ununbium”฀(which฀literally฀means฀112),฀is฀ used฀to฀name฀new฀elements฀until฀IUPAC’s฀naming฀committee฀decides฀upon฀a฀perma- nent฀name.

ISOTOPES:฀There฀are฀four฀isotopes฀of฀ununbium฀ranging฀from฀Uub-277฀to฀Uub-285.฀They฀ have฀half-lives฀ranging฀from฀0.24฀milliseconds฀to฀10฀minutes฀for฀Uub-285.฀All฀are฀artifi- cially฀produced,฀are฀radioactive,฀and฀are฀unstable.

ELECTRON฀CONFIGURATION ฀ Energy฀Levels/Shells/Electrons฀ Orbitals/Electrons

s2,฀p6

฀ 3-M฀=฀18฀

s2,฀p6,฀d10

฀ 4-N฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 5-O฀=฀32฀

s2,฀p6,฀d10,฀f14

฀ 6-P฀=฀18฀

s2,฀p6,฀d10

฀ 7-Q฀=฀2฀

s2