Actinium [ækˈtɪnɪəm]– (Greek actis (aktinos) – light] – chemical radioactive element, designation Ac (lat. actinum), atn. 80, mass number of the most stable isotope 227. A. is a silvery-white metal, close to 1050oC. Found naturally in uranium and thorium ores. The mixture with beryllium is used to prepare neutron sources.
Ex. The presence of actinium in uranium ores can also complicate the processing and disposal of radioactive waste materials generated during the mining and extraction processes.