roentgenium
[ rent-gen-ee-uhm, -jen-, ruhnt- ]
nounChemistry, Physics.
a superheavy, synthetic radioactive element with a very short half-life. Symbol: Rg; atomic number: 111.
Origin of roentgenium
1First recorded in 2000–05; named after German physicist Wilhelm Konrad Roentgen.
- Formerly u·nu·nun·i·um [uh-nuh-nuhn-ee-uhm], /ə nəˈnʌn i əm/, el·e·ment 111 .
Words Nearby roentgenium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
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 Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Browse