meitnerium(redirected from unnilennium)
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Related to unnilennium: Element 109
n. Symbol Mt
An artificially produced radioactive element with atomic number 109 that has known isotopes with mass numbers ranging from 265 to 279. The isotope with the longest confirmed half-life (0.7 seconds) is Mt-268. See Periodic Table.
[After Lise Meitner.]
(Elements & Compounds) a synthetic element produced in small quantities by high-energy ion bombardment. Symbol: Mt; atomic no: 109
[C20: named after Lise Meitner]
Symbol Mt A synthetic, radioactive element that is produced by bombarding bismuth with iron ions. Its most stable isotope has a half-life of 70 milliseconds. Atomic number 109. See Periodic Table.
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|Noun||1.||meitnerium - a radioactive transuranic element|