zh-hans:丰度zh-hans:元素周期表

[Rn] 5f 6d 7s
（计算值）
2, 8, 18, 32, 32, 15, 2
（预测）

面心立方（预测）

䥑（Meitnerium）是人工合成的放射性化学元素，化学符号为Mt，原子序为109。䥑是9 (VIIIB)族最重的元素，但由于没有足够稳定的䥑同位素，因此未能通过化学实验来验证䥑的性质是否符合周期律。䥑于1982年首次合成，其最稳定同位素为Mt，半衰期为7.6秒。

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