roentgen rontgen (#) Fr.: roentgen A unit of radiation exposure defined as a charge release rate of 258 micro-coulombs per kilogram of air. Named after the German physicist Wilhelm Konrad Röntgen (1845-1923), one of the early investigators of radioactivity. |
roentgenium rontgeniom (#) Fr.: roentgenium An artificially produced radioactive chemical element; symbol Rg. Atomic number 111; mass number of most stable isotope 272; melting point, boiling point, specific gravity, and valence unknown. Named after the German physicist Wilhelm Konrad Röntgen (1845-1923), one of the early investigators of radioactivity. |