Roentgenium

It was discovered by Peter Armbruster, Gottfried Münzenber and their team working at the Gesellschaft fur Schwerionenforschung (GSI) in Darmstadt, Germany on December 8, 1994. Only three atoms of it were observed (all ²⁷²Rg), by the fusion of bismuth-209 and nickel-64 in a linear accelerator. (Nickel was bombarded onto the bismuth target.)

The name roentgenium was accepted as a permanent name on November 1, 2004 in honor of Wilhelm Roentgen; before this date, the element was known under the temporary IUPAC systematic element name unununium, symbol Uuu). Some research has referred to it as eka-gold.

The official baptism took place at GSI, on Friday November 17, 2006, in the presence of Annette Schavan, the Federal German Minister of Research.

One of the super-heavy atoms. It is a synthetic transition element whose presence in Group 11 probably would appear as a heavy, solid, shiny metal. Due to the inert pair effect, it should be colored like gold.

Twelve isotopes of roentgenium are known. The longest-lived of these is ²⁸⁰Rg which decays through alpha decay and has a half-life of 3.6 seconds. The shortest-lived isotope is ²⁷²Rg which decays through alpha decay and has a half life of 2.0 ms. The other known isotope, ²⁷⁹Rg, decays through alpha decay and has a half-life of 0.17 seconds.

Isotope	Atomic Mass	Half-Life
²⁷²Rg	272.15362	2.0 ms
²⁷³Rg	273.15368	~5 ms
²⁷⁴Rg	274.15571	6.4 ms
²⁷⁵Rg	275.15614	~10 ms
²⁷⁶Rg	276.15849	~100 ms
²⁷⁷Rg	277.15952	~1 seconds
²⁷⁸Rg	278.16160	~1 seconds
²⁷⁹Rg	279.16247	0.17 seconds
²⁸⁰Rg	280.16447	3.6 seconds
²⁸¹Rg	281.16537	~1 minutes
²⁸²Rg	282.16749	~4 minutes
²⁸³Rg	283.16842	~10 minutes

Roentgenium Data

Atomic Structure

Number of Electrons (with no charge): 111
Number of Neutrons (most common/stable nuclide): 161
Number of Protons: 111

Chemical Properties

No Chemical properties information is currently available.

Physical Properties

Atomic Mass Average: 272
Boiling Point:
Coefficient of Lineal Thermal Expansion/K^-1: N/A
Conductivity:

Electrical:
Thermal:
Description:

Synthetically produced radioactive super heavy element with an extremely short half life that does not occur in nature.

Regulatory / Health

Levels In Humans:
Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
- Blood/mg dm^-3: nil
- Bone/p.p.m: nil
- Liver/p.p.m: nil
- Muscle/p.p.m: nil
- Daily Dietary Intake: nil
- Total Mass In Avg. 70kg human: nil

Who / Where / When / How

Discoverer: S.Hofmann, V.Ninov, F.P.Heßberger, P.Armbruster, H.Folger, G.Münzenberg, H.J.Schött
Discovery Location: Darmstadt Germany
Discovery Year: 1994
Name Origin:

Named for Wilhelm Conrad Roentgen who discovered X-rays in 1895.
Abundance:
- Earth's Crust/p.p.m.: nil
- Seawater/p.p.m.: nil
- Atmosphere/p.p.m.: nil
- Sun (Relative to H=1E¹²): N/A
Sources:

Syntheticly produced element normally produced by fusing two lighter elements in a heavy ion accelerator.
Uses:

Of research interest only.
Additional Notes:

In August of 2003 the International Union of Pure and Applied Chemistry (IUPAC) announced the official naming of this element (source: IUPAC, Element 111 is named roentgenium.

Transition Metals
Group	3 (IIIB)	4 (IVB)	5 (VB)	6 (VIB)	7 (VIIB)	8 (VIIIB)	9 (VIIIB)	10 (VIIIB)	11 (IB)	12 (IIB)
Period 4	21 Sc 44.95	22 Ti 47.86	23 V 50.94	24 Cr 51.99	25 Mn 54.93	26 Fe 55.84	27 Co 58.93	28 Ni 58.69	29 Cu 63.54	30 Zn 65.39
Period 5	39 Y 88.90	40 Zr 91.22	41 Nb 92.90	42 Mo 95.94	43 Tc 98.00	44 Ru 101.0	45 Rh 102.9	46 Pd 106.4	47 Ag 107.8	48 Cd 112.4
Period 6	57 La 138.9	72 Hf 178.4	73 Ta 180.9	74 W 183.8	75 Re 186.2	76 Os 190.2	77 Ir 192.2	78 Pt 195.0	79 Au 196.9	80 Hg 200.5
Period 7	89 Ac 227.0	104 Rf 261.0	105 Db 262.0	106 Sg 266.0	107 Bh 264.0	108 Hs 269.0	109 Mt 268.0	110 Ds 269.0	111 Rg 272.0	112 Uub 277.0

1s²
2s²	2p⁶
3s²	3p⁶	3d¹⁰
4s²	4p⁶	4d¹⁰	4f¹⁴
5s²	5p⁶	5d¹⁰	5f¹⁴
6s²	6p⁶	6d¹⁰
7s¹