Roentgenium 111

Atomic No. Order:

Alphabetic Order:

Periodic Table

2,8,18,32,

32,18,1

Cu
29

Ag
47

Au
79

Rg
111

Uhu
161

Buu
211

Roentgenium

Symbol

Atomic Number

111

Relative Atomic Mass
¹²C = 12.0000

[ 280 ]

Significant Atomic Mass

283
Neutrons 172

Atomic Radius pm

First Ionisation Energy
kJ mol ^-1

Electronegativity

Density kg m ^-3

Molar Volume cm ³

Thermal Conductivity
W m ^-1 K ^-1

Melting Point K

Boiling Point K

Number of Isotopes

272   Rg 1.5 ms (272.1535)
273   Rg
279   Rg
280   Rg   3.6 seconds

Inner + outer Shells

= 7

Inner + outer Orbitals

= 111

Filling Orbital

7s ¹

Ground State Electron Configuration

[Rn]

5f ¹⁴

6d ¹⁰

7s ¹

Ground State Electron
Configuration with
free Orbitals (n= 7)

0,0,0,0,0,0, 7

Ground State Electron Configuration with compressed Orbitals (n= 162)

0,0,0,0,18,54,90

Singularity

280

162

	s		p	d	f	g	h	i	j
1	2
2	2		6
3	2		6	10
4	2		6	10	14
5	2		6	10	14	18
6	2		6	10	14	18	22
7	1	1	6	10	14	18	22	26
8

Term Symbol

Obsolete Names

Unununium, Uuu
eka-aurum, eka-gold ,eka-Au

Discovery

S. Hofmann, V. Ninov, F. P. Hessberger, P. Armbruster, H. Folger, G. Münzenberg, H. J. Schott, A. G. Popeko, A. V. Yeremin, A. N. Andreyev, S. Saro, R. Janik, M. Lein

Element 111 is named roentgenium

Following the 80th Meeting of the Bureau in Bled, Slovenia, the name roentgenium for the element of atomic number 111, with symbol Rg was officially approved as of 1 November 2004. The IUPAC Council, at its meeting at Ottawa, Canada in 2003, delegated the authority to approve a name for the element of atomic number 111 to the Bureau.

Name Derived From

Röntgen also spelled ROENTGEN (b. March 27, 1845, Lennep, Prussia [now Remscheid, Ger.]--d. Feb. 10, 1923, Munich, Ger.), German physicist who was a recipient of the first Nobel Prize for Physics, in 1901, for his discovery of X rays, which heralded the age of modern physics and revolutionized diagnostic medicine.
Röntgen studied at the Polytechnic in Zürich and then was professor of physics at the universities of Strasbourg (1876-79), Giessen (1879-88), Würzburg (1888-1900), and Munich (1900-20). His research also included work on elasticity, capillary action of fluids, specific heats of gases, conduction of heat in crystals, absorption of heat by gases, and piezoelectricity.

S. Hofmann, V. Ninov, F. P. Hessberger, P. Armbruster, H. Folger, G. Münzenberg, H. J. Schott, A. G. Popeko, A. V. Yeremin, A. N. Andreyev, S. Saro, R. Janik, M. Leino. "The new element 111", Z. Phys. A 350, 281282 (1995).

In bombardments of ²⁰⁹Bi targets with ⁶⁴Ni using the velocity selector SHIP facility to discriminate in favor of the fused product, ²⁷³111, three sets of localized alpha-decay chains were observed with position sensitive detectors. The origin was assigned to the isotope ²⁷²Rg, one neutron removed from the compound nucleus. Applying the evaluation criteria to the case of Roentgenium, the data are of the highest quality. However, there is internal redundancy with just two pairs of data. Chains 2 and 3 have mutually concordant alpha energies, but ones ascribed to the previously unknown ²⁶⁴Bh. Chains 1 and 3 also have mutually concordant alpha energies, but these are ascribed to the previously unknown ²⁶⁸Mt. There is no redundancy involving properties of known daughters for verification purposes. Chain 2 is most compelling, matching the known ²⁶⁰Db energy and lifetime. Unambiguous observation of its daughter ²⁵⁶Lr in this sequence would have been sufficient to secure the discovery.

The Hofmann et al. collaboration reports* on three new chains originating from ²⁷²Rg in the ⁶⁴Ni + ²⁰⁹Bi reaction. This brings the number of events to six, three of which proceed through the known descendants ²⁶⁰Db and ²⁵⁶Lr with decay property agreement. The latter in toto provide a strong linkage for the third, fourth, and sixth chains despite some scatter in ²⁶⁴Bh alpha energies and an incomplete alpha determination from ²⁷²Rg in the fourth chain.

Priority of discovery of Roentgenium by the Hofmann et al. collaboration has now been confirmed owing to the additional convincing observations in S. Hofmann, F. P. Hessberger, D. Ackermann, G. Münzenberg, S. Antalic, P. Cagarda, B. Kindler, J. Kojouharova, M. Leino, B. Lommel, R. Mann, A. G. Popeko, S. Reshitko, S. Saro, J. Uusitalo, A. V. Yeremin. "New results on elements 111 and 112", Eur. Phys. J. A 14, 147157 (2002).

Roentgenium's most stable isotope, roentgenium-280, has a half-life of about 3.6 seconds. It decays into meitnerium-276 through alpha decay

APSIDIUM ©	Created:		2002-09-01		111.pdf
	Page update:		2004-12-12		111.pdf