A transuranic element of atomic number 103. It was discovered in 1961 by bombardment of californium in a cyclotron with boron nuclei. Other isotopes were prepared in 1965 at Dubna. The atomic weight of the most stable isotope is 256, having a half-life of 35 seconds. Symbol Lr.

a radioactive transuranic element synthesized from californium

Lawrencium (IPA: ), also called eka-lutetium, is a radioactive synthetic element in the periodic table that has the symbol Lr and atomic number 103. Its most stable isotope is 262Lr, with a half-life of approximately 4 hours. Lawrencium is synthesized from californium and has no known uses.