meitnerium(redirected from Unnilenium)
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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|