from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun An artificially produced radioactive element with atomic number 105. The isotope with mass number 262 has the longest confirmed half-life (35 seconds), although longer half-lifes have been reported for some of its heavier isotopes. cross-reference: Periodic Table.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun A
transuranicchemical element (symbol Db) with atomic number105.
- noun chemistry, obsolete A rejected name for
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a transuranic element
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
Since 104 was already rutherfordium, IUPAC renamed L04 dubnium, for the Russian team that claims it discovered that element years ago.
Dubna has already been enshrined in the periodic table with dubnium element 105, so the Russians chose to honor Georgi N.
The isotope with 177 neutrons decays down to dubnium (atomic number 105), whereas the isotope with 176 neutrons decays down to roentgenium (atomic number 111).