Noun
a radioactive transuranic element
Source: WordNetExperimental chemistry Unambiguous determination of the chemical characteristics of roentgenium has yet to have been established citation due to the low yields of reactions that produce roentgenium isotopes. Source: Internet
The atomic radius of roentgenium is expected to be around 138 pm. Source: Internet
The most stable known roentgenium isotope, 282 Rg, is also the heaviest known roentgenium isotope; it has a half-life of 2.1 minutes. Source: Internet
The undiscovered isotope 287 Rg has been predicted to be the most stable towards beta decay ; citation however, no known roentgenium isotope has been observed to undergo beta decay. Source: Internet