<page_title> Isotopes of roentgenium </page_title> <section_title> List of isotopes </section_title> <table> <cell> 272Rg <col_header> nuclide symbol </col_header> </cell> <cell> 272.15327(25)# <col_header> isotopic mass (u) </col_header> </cell> </table>
The lightest isotope of roentgenium is roentgenium-272.