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Name , symbol , atomic number Bohrium, Bh, 107
Element category Transition metals
Group , period , block 7 , 7 , d
CAS number 54037-14-8
Atomic mass 262,1229 u
Electron configuration [ Rn ] 5 f 14 6 d 5 7 s 2 (?)
1. Ionization energy 7th.7 (5) eV743 kJ / mol
2. Ionization energy 17th.5 (5) eV1 690 kJ / mol
3. Ionization energy 26th.7 (5) eV2 580 kJ / mol
4. Ionization energy 37.3 (5) eV3 600 kJ / mol
5. Ionization energy 49.0 (5) eV4 730 kJ / mol
isotope NH t 1/2 ZA ZE (M eV ) ZP
261 operating hours {syn.} 11.8 ms
262 hours {syn.}
264 operating hours {syn.} 440 ms
267 hours {syn.} 17 s α
For other isotopes see list of isotopes
Hazard and safety information
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used.
Unless otherwise noted, the data given apply to standard conditions .

Bohrium (formerly: " Eka -Rhenium") is an exclusively artificially produced chemical element with the element symbol Bh and the atomic number 107 and is one of the transactinoids ( 7th period , d-block). In the periodic table of the elements it is in the 7th  IUPAC group , the manganese group . All Bohrium isotopes are radioactive. It was named after the Danish physicist Niels Bohr (not to be confused with boron ).

Niels Bohr

Bohrium was first produced on October 6, 1976 by a Soviet research group headed by Yuri Oganessian at the Institute for Nuclear Research near Dubna , but it was not recognized as such. The production therefore officially goes back to the Society for Heavy Ion Research in Darmstadt, which produced the element on March 27, 1981 and suggested the name Nielsbohrium. It was initially called Unnilseptium (symbol Us) and has been given its current name since the IUPAC recommended it in 1994 . It is also known as Eka - Rhenium .

safety instructions

There is no classification according to the CLP regulation or other regulations. Only a few atoms of this element can be produced at the same time and thus far too few for chemical or physical danger.

Web links

Commons : Bohrium  - collection of images, videos and audio files
Wiktionary: Bohrium  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. a b c d e entry on bohrium in Kramida, A., Ralchenko, Yu., Reader, J. and NIST ASD Team (2019): NIST Atomic Spectra Database (ver. 5.7.1) . Ed .: NIST , Gaithersburg, MD. doi : 10.18434 / T4W30F ( ). Retrieved June 13, 2020.
  2. a b c d e entry on bohrium at WebElements, , accessed on June 13, 2020.
  3. The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this element has either not yet been classified or a reliable and citable source has not yet been found.