[ 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.
THINK YOU’VE GOT A HANDLE ON THIS US STATE NICKNAME QUIZ?
Did you ever collect all those state quarters? Put them to good use on this quiz about curious state monikers and the facts around them.
Question 1 of 8
Mississippi’s nickname comes from the magnificent trees that grow there. What is it?
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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
Scientific definitions for roentgenium
[ rĕnt-gĕn′ē-əm, -jĕn′-, rŭnt-, rœnt-gĕn′- ]
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.