found: Work cat.: Thompson, S.G. Chemical properties of berkelium, 1950:p. 3 (transuranium element)
found: Thompson, S.G. The new element berkelium (atomic number 97), 1950:abstr. (the name berkelium, symbol Bk, is proposed for element 97)
found: Emsley, J. Nature's building blocks, 2011(Berkelium; Bk; first produced on 19 Dec. 1949 at the Univ. of California at Berkeley; radioactive metallic element that is a member of the actinide group (row 5f) of the periodic table)
found: WebElements website, Nov. 1, 2012(Berkelium is a radioactive rare earth metal, named after the University of California at Berkeley; Symbol: Bk; Atomic number: 97; Group name: Actinoid; Period in periodic table: 7 (actinoid); Block in periodic table: f-block; Classification: Metallic)
found: ChemicalElements.com, Nov. 1, 2012(Berkelium. Symbol: Bk. Atomic Number: 97. Atomic Mass: (247.0) amu. Number of Protons/Electrons: 97. Number of Neutrons: 150. Classification: Rare Earth)
found: Wikipedia, Nov. 1, 2012(Berkelium is a transuranic radioactive chemical element with the symbol Bk and atomic number 97, a member of the actinide and transuranium element series)
