Roentgenium Element Facts

Wilhelm Conrad Roentgen

Roentgenium is named after Wilhelm Roentgen, who was awarded the first ever Physics Nobel Prize in 1901 for his discovery of x-rays.


Data Zone

Classification: Roentgenium is a transition metal
Atomic weight: (281), no stable isotopes
State: solid (presumed)
Melting point:
Boiling point:
Electrons: 111
Protons: 111
Neutrons in most abundant isotope: 170
Electron shells: 2,8,18,32,32,17,2
Electron configuration: [Rn] 5f14 6d9 7s2
Density @ 20oC:
Show more, including: Heats, Energies, Oxidation, Reactions, Compounds, Radii, Conductivities
Atomic volume:
Specific heat capacity
Heat of fusion
Heat of atomization
Heat of vaporization
1st ionization energy
2nd ionization energy
3rd ionization energy
Electron affinity
Minimum oxidation number
Min. common oxidation no.
Maximum oxidation number
Max. common oxidation no.
Electronegativity (Pauling Scale)
Polarizability volume
Reaction with air
Reaction with 15 M HNO3
Reaction with 6 M HCl
Reaction with 6 M NaOH
Atomic radius
Ionic radius (1+ ion)
Ionic radius (2+ ion)
Ionic radius (3+ ion)
Ionic radius (1- ion)
Ionic radius (2- ion)
Ionic radius (3- ion)
Thermal conductivity
Electrical conductivity
Freezing/Melting point:

Discovery of Roentgenium

Roentgenium was first made by research scientists at the Heavy Ion Research Laboratory in Darmstadt, Germany in 1994.

The scientists bombarded nickel-64 with bismuth-209 in a heavy ion accelerator.

The element is named after physicist Wilhelm Conrad Röntgen who discovered X-rays in 1895.

Appearance and Characteristics

Harmful effects:

Roentgenium is harmful due to its radioactivity.


Roentgenium is a synthetic radioactive metal and has only been produced in minute amounts.

Uses of Roentgenium

Roentgenium is of research interest only.

Abundance and Isotopes

Abundance earth’s crust: nil

Abundance solar system: parts per billion by weight, parts per trillion by moles

Cost, pure: $ per 100g

Cost, bulk: $ per 100g

Source: Roentgenium is a synthetic radioactive metal, created via nuclear bombardment, and has only been produced in minute amounts. Roentgenium is produced by bombarding 209Bi with 64Ni in a heavy ion accelerator.

Isotopes: Roentgenium has 7 isotopes whose half-lives are known, with mass numbers from 272 to 282. None are stable. The most stable isotope is 281Rg, with a half-life of 23 seconds.

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