Lawrencium

Lawrencium (pronounced /ləˈrɛnsiəm/, lə-REN-see-əm) is a radioactive synthetic element with the symbol Lr (formerly Lw) and atomic number 103. Its most stable known isotope is Lr, with a half-life of approximately 3.6 hours. Little is known of the chemistry but there is strong evidence for the formation of a trivalent ion in aqueous solution, confirming lawrencium's place as the last member of the actinoids. Although lawrencium is often placed as... more

Lawrencium (pronounced /ləˈrɛnsiəm/, lə-REN-see-əm) is a radioactive synthetic element with the symbol Lr (formerly Lw) and atomic number 103. Its most stable known isotope is Lr, with a half-life of approximately 3.6 hours. Little is known of the chemistry but there is strong evidence for the formation of a trivalent ion in aqueous solution, confirming lawrencium's place as the last member of the actinoids. Although lawrencium is often placed as the last member of the 5f-block, it can also be regarded as the first member of the 6d-block (see extended periodic table). Lawrencium was made by Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh, and Robert M. Latimer on February 14, 1961 at the Lawrence Radiation Laboratory (now called Lawrence Berkeley National Laboratory) on the University of California, Berkeley campus. It was produced by bombarding a three milligram target composed of three isotopes of californium with boron-10 and B-11 ions in the Heavy Ion Linear Accelerator (HILAC).... less