dubnium

American  

[doob-nee-uhm, duhb-] / ˈdub ni əm, ˈdʌb- /

noun

Chemistry, Physics.

1. a superheavy, synthetic, radioactive element with a very short half-life. Db; 105.

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dubnium British  

/ ˈdʌbnɪəm /

noun

1. a synthetic transactinide element produced in minute quantities by bombarding plutonium with high-energy neon ions. Symbol: Du; atomic no 105 See hahnium

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dubnium Scientific  

/ do̅o̅b′nē-əm /

1. A synthetic, radioactive element that is produced from californium, americium, or berkelium. Its most long-lived isotopes have mass numbers of 258, 261, 262, and 263 with half-lives of 4.2, 1.8. 34, and 30 seconds, respectively. Atomic number 105.

2. See Periodic Table

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Etymology

Origin of dubnium

First recorded in 1970–75; officially assigned to element 105 in 1997; named after Dubna, the town in Russia where it was first produced; see -ium ( def. )