Meitnerium

properties
[ Rn ] 5 f 14 6 d 7 7 s 2 109 m Periodic table
General
Name , symbol , atomic number	Meitnerium, Mt, 109
Element category
Group , period , block	9 , 7 , d
CAS number	54038-01-6
Atomic
Atomic mass	268 u
Electron configuration	[ Rn ] 5 f 14 6 d 7 7 s 2
1. Ionization energy	801 kJ / mol
Physically
Isotopes
isotope NH t 1/2 ZA ZE (M eV ) ZP
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 .

Meitnerium (formerly: " Eka -Iridium") is an artificial chemical element with the element symbol Mt and the atomic number 109. It is one of the transactinoids and is in the 9th  IUPAC group in the periodic table of the elements and thus to the cobalt group . It was named in honor of the Austrian-Swedish physicist Lise Meitner .

history

Meitnerium was first produced in 1982 (and then again in February 1988) at the Society for Heavy Ion Research in Darmstadt by bombarding bismuth with iron . It was initially called Unnilennium (symbol Une), since 1997 the current name.

properties

Meitnerium is an extremely short-lived radioactive metal . So far, seven isotopes (here radionuclides ) have been generated. The longest-lived isotope is ²⁷⁶ Mt, the half-life of which is 720 milliseconds. Because of this very rapid decay , little is known about the other properties of the element. Nevertheless, it is assumed that meitnerium is largely colored silver-gray. Meitnerium occurs only in synthesized form.

safety instructions

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

Web links

Commons : Meitnerium  - collection of images, videos and audio files

Wiktionary: Meitnerium  - explanations of meanings, word origins, synonyms, translations

• Nuclide map at the National Nuclear Data Center

Individual evidence

1. ↑ Entry on meitnerium at WebElements, https://www.webelements.com , accessed on June 13, 2020.
2. ↑ 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.
3. ^ Names and Symbols of Transfermium Elements (IUPAC Recommendations 1997). (PDF; 167 kB).
4. ↑ Meitnerium (Mt) - Periodic Table of the Elements (PSE). Retrieved July 27, 2018 .