MESOTHORIUM
Source: 567
‖Mes′o‐tho″ri‐um (?), n. [[NL.; meso- + thorium.]] (Chem.) A radioactive product intermediate between thorium and radiothorium, with a period of 5.5 years.
Source: 567
‖Mes′o‐tho″ri‐um (?), n. [[NL.; meso- + thorium.]] (Chem.) A radioactive product intermediate between thorium and radiothorium, with a period of 5.5 years.