lawrencium

An artificial transplutonium element; atomic no. 103; atomic wt. 262.11. [E.O. Lawrence, U.S. physicist and Nobel laureate, 1901–1958]

* * *

law·ren·ci·um lȯ-'ren(t)-sē-əm n a short-lived radioactive element that is produced artificially from californium symbol Lr see ELEMENT (table)

Law·rence 'lȯr-ən(t)s, 'lär- Ernest Orlando (1901-1958)

American physicist. Lawrence was associated with the University of California, Berkeley, for virtually all of his research career. He was responsible for the establishment of the Radiation Laboratory at Berkeley and was appointed its director in 1936. He first conceived of the cyclotron, a subatomic particle accelerator, in 1929, and in 1939 he was awarded the Nobel Prize for Physics for its invention. Using the cyclotron Lawrence produced radioactive phosphorus and other isotopes for medical use, including iodine for the first therapeutic treatment of hyperthyroidism. In 1961 element 103 was named lawrencium in his honor.

* * *

law·ren·ci·um (Lr) (law-renґse-əm) [Ernest Orlando Lawrence, American physicist, 1901–1958; builder of the first cyclotron for the production of high-energy particles and winner of the Nobel prize for physics in 1939] the chemical element of atomic number 103, atomic weight 257; produced in 1961 by bombardment of californium isotopes of mass 250, 251, and 252.