Meitnerium

Meitnerium is a chemical element with the symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds. Meitnerium was first created in 1982 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Lise Meitner.