থৰুৱাথ’ৰিয়াম ডাইঅক্সাইড
থ’ৰিয়াম (Assamese)
থ’ৰিয়াম (Assamese)
1. Thorium is a chemical element. It has the symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive gray when it is exposed to air, forming thorium dioxide... from wikipedia.org