Periodic Table


July 10, 2012, 1:18 pm
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Image of Lise Meitner, for whom the element was named after. (Source:

Previous Element: Hassium

Next Element: Darmstadtium


Physical Properties
Color ---
Phase at Room Temp. ---
Density (g/cm3) ---
Hardness (Mohs) ---
Melting Point (K) ---
Boiling Point (K) ---
Heat of Fusion (kJ/mol) ---
Heat of Vaporization (kJ/mol) ---
Heat of Atomization (kJ/mol) ---
Thermal Conductivity (J/m sec K) ---
Electrical Conductivity (1/mohm cm) ---
Source Synthetic
Atomic Properties
Electron Configuration [Rn]7s25f146d7
Number of Isotopes 5 (0 natural)
Electron Affinity (kJ/mol) ---
First Ionization Energy (kJ/mol) ---
Second Ionization Energy (kJ/mol) ---
Third Ionization Energy (kJ/mol) ----
Electronegativity ---
Polarizability (Å3) ---
Atomic Weight 266
Atomic Volume (cm3/mol) ---
Ionic Radius2- (pm) ---
Ionic Radius1- (pm) ---
Atomic Radius (pm) ---
Ionic Radius1+ (pm) ---
Ionic Radius2+ (pm) ---
Ionic Radius3+ (pm) ---
Common Oxidation Numbers +3
Other Oxid. Numbers ---
In Earth's Crust (mg/kg) ---
In Earth's Ocean (mg/L) ---
In Human Body (%) 0%
Regulatory / Health
CAS Number 54038-01-6
OSHA Permissible Exposure Limit (PEL) No limits
OSHA PEL Vacated 1989 No limits
NIOSH Recommended Exposure Limit (REL) No limits
Mineral Information Institute
Jefferson Accelerator Laboratory

Meitnerium was created and identified by two physicists in Darmstadt, Germany on August 29, 1982 at the Heavy Ion Research Laboratory.

The element Meitnerium was named after Lise Meitner, an Austrian physicist. Its atomic symbol is Mt, Its atomic number is 109 and its atomic mass is 266.14. Meitnerium is classifed as a transition metal, one of four commonly used categories of the Periodic Table (the remaining groups are: main group elements, lanthanides, and actinides).

Meitnerium is a synthetic radioactive element produced through a cold fusion reaction process, also known as low energy nuclear reaction, that involves bombarding Bismuth 209 (209Bi) with a nuclei of Iron 58 (58Fe):

 209Bi + 58Fe  →  266Mt

Only 10 atoms of Meitnerium have been created and it will probably never be isolated in observable quantities. 

Meitnerium has no known industrial uses, nor is it known to perform any specific biological role.


The physical properties—color, structure, density and hardness— of Meitnerium remain unknown or poorly understood. But it is presumed to be a metallic grey, silvery-white element.

Meitnerium has seven energy levels: 

  • First Energy Level:
  • Second Energy Level:
  • Third Energy Level: 18 
  • Fourth Energy Level: 32 
  • Fifth Energy Level: 32 
  • Sixth Energy Level: 15 
  • Seventh Energy Level: 2

Electron configuration:


Meitnerium has an extremely short half life of approximately 3.4 milliseconds (3.4x10-3secs).

First synthesis

Meitnerium was first synthesized for the first time on August 29, 1982 by a German researchers Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung) in Darmstadt, Germany. The scientists bombarded a target of bismuth-209 with accelerated nuclei of iron-58 and detected a single atom of the isotope meitnerium-266

Further reading



Survey, U. (2012). Meitnerium. Retrieved from


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