Meitnerium is element number 109, with the symbol Mt. Its name comes from Lise Meitner.
Atomic number 109(276)
MtMeitneriumマイトネリウム (maitoneriumu)
Symbol
Mt
Atomic weight
(276)
Place in the table
Period 7 · Group 9
The number in parentheses is not an atomic weight. It is the mass number of one radioactive isotope of the element.
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Found before element 108
Meitnerium was found in West Germany (as it was then) in 1982, made by smashing iron (number 26) into bismuth (number 83). Its name was decided in 1997.
It was found two years earlier than element 108, hassium.
Where it sits on the table
Meitnerium is in the seventh row of Group 9, at the bottom of the column with cobalt, rhodium and iridium.
Think about it
Q1What is 83 + 26?
Q2How many elements named after people can you find in the Room of the Elements?
Q3Can you name the Group 9 elements from the top?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Bohrium, hassium and meitnerium were all confirmed in 1993 and named in 1997.