Roentgenium: the essentials

Roentgenium, was discovered on 8th December 1994 at the GSI in Darmstadt, Germany. The interested reader should consult the on-line version of Creating Super Heavy Elements for a fascinating insight into research on "super-heavy" atoms.

Chemically, roentgenium should be in the same group as the elements copper, silver, and gold (Group 11).

Roentgenium: historical information

Roentgenium was discovered by S. Hofmann, V. Ninov, F. P. Hessberger, P. Armbruster, H. Folger, G. Münzenberg, and others in 1994 at Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany.. Origin of name: the proposed name roentgenium has yet ot be accepted formally, but lies within the long established tradition of naming elements to honour famous scientists. Wilhelm Conrad Roentgen discovered X-rays in 1895.

Element 111, roentgenium, was discovered towards the end of 1994 at the GSI in Darmstadt, Germany. Three atoms of an isotope 272Uuu were produced in reactions between 209Bi targets and 64Ni projectiles. To achieve this, the nickel atoms were accelerated to high energies by the heavy ion accelerator UNILAC at GSI and directed onto a lead target.

Roentgenium around us Read more »

Element 111, roentgenium, has no biological role.

Roentgenium is a synthetic element that is not present in the geosphere.

Abundances for roentgenium in a number of different environments. More abundance data »
Location ppb by weight ppb by atoms Links
Universe (no data) (no data) Chemical elements abundance by weight in the universe on a miniature periodic table spark table
Crustal rocks (no data) (no data) Chemical elements abundance by weight in the earth's crust on a miniature periodic table spark table
Human (no data) ppb by weight (no data) atoms relative to C = 1000000 Chemical elements abundance by weight in humans on a miniature periodic table spark table

Physical properties Read more »

Heat properties Read more »

Crystal structure Read more »

The solid state structure of roentgenium is: .

Roentgenium: orbital properties Read more »

Roentgenium atoms have 111 electrons and the shell structure is The ground state electronic configuration of neutral Roentgenium is [Rn].5f14.6d10.7s1 (a guess based upon that of gold) and the term symbol of Roentgenium is 2S1/2 (a guess based upon guessed electronic structure).


Isolation: only a few atoms of element 111, roentgenium, have ever been made through a nuclear reaction involving fusion of an isotope of bismuth, 209Bi, with one of nickel, 64Ni.

209Bi + 64Ni → 272Rg + 1n

Isolation of an observable quantity has never been achieved, and may well never be.

Roentgenium isotopes Read more »

Table. Stables isotopes of roentgenium.
Isotope Mass
(atom %)
spin (I)
moment (μ/μN)

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