roentgenium
[ rent-gen-ee-uhm, -jen-, ruhnt- ]
/ rɛntˈgɛn i əm, -ˈdʒɛn-, rʌnt- /
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noun Chemistry, Physics.
a superheavy, synthetic radioactive element with a very short half-life. Symbol: Rg; atomic number: 111.
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Formerly u·nu·nun·i·um [uh-nuh-nuhn-ee-uhm], /ə nəˈnʌn i əm/, el·e·ment 111 .
Origin of roentgenium
First recorded in 2000–05; named after German physicist Wilhelm Konrad Roentgen.
Words nearby roentgenium
Roeg, roemer, Roentgen, roentgen equivalent man, roentgenism, roentgenium, roentgenize, roentgeno-, roentgenogram, roentgenograph, roentgenography
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
Scientific definitions for roentgenium
roentgenium
[ rĕnt-gĕn′ē-əm, -jĕn′-, rŭnt-, rœnt-gĕn′- ]
Rg
An artificially produced radioactive element with a mass number of 280. Its most stable known isotope has a half-life of 3.6 seconds. Atomic number 111. See Periodic Table.
The American Heritage® Science Dictionary
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