meitnerium

American  

[mahyt-nur-ee-uhm] / maɪtˈnɜr i əm /

noun

Chemistry, Physics.

1. a superheavy, synthetic, radioactive element with a very short half-life. Mt; 109.

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meitnerium British  

/ ˈmaɪtnɪərɪəm /

noun

1. a synthetic element produced in small quantities by high-energy ion bombardment. Symbol: Mt; atomic no: 109

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meitnerium Scientific  

/ mīt-nûr′ē-əm /

1. A synthetic, radioactive element that is produced by bombarding bismuth with iron ions. Its most long-lived isotopes have mass numbers of 266 and 268 with half-lives of 3.4 milliseconds and 70 milliseconds, respectively. Atomic number 109.

2. See Periodic Table

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Etymology

Origin of meitnerium

First recorded in 1975–80; officially assigned to element 109 in 1997; named after Austrian physicist Lise Meitner; see -ium ( def. )