Bohrium

properties
[ Rn ] 5 f 14 6 d 5 7 s 2 (?) 107 hours Periodic table
General
Name , symbol , atomic number	Bohrium, Bh, 107
Element category	Transition metals
Group , period , block	7 , 7 , d
CAS number	54037-14-8
Atomic
Atomic mass	262,1229 u
Electron configuration	[ Rn ] 5 f 14 6 d 5 7 s 2 (?)
1. Ionization energy	7th.7 (5) eV ≈ 743 kJ / mol
2. Ionization energy	17th.5 (5) eV ≈ 1 690 kJ / mol
3. Ionization energy	26th.7 (5) eV ≈ 2 580 kJ / mol
4. Ionization energy	37.3 (5) eV ≈ 3 600 kJ / mol
5. Ionization energy	49.0 (5) eV ≈ 4 730 kJ / mol
Physically
Isotopes
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
Radioactive
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

• Nuclide map at the National Nuclear Data Center

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 ( https://physics.nist.gov/asd ). Retrieved June 13, 2020.
2. ↑ ^{a b c d e} entry on bohrium at WebElements, https://www.webelements.com , 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.