What element has the symbol 'Lr'?

The story behind the answer

Lr is the symbol for Lawrencium, element 103. The other options have different symbols: Lithium is Li, Lanthanum is La, and Lutetium is Lu. Lawrencium sits at the end of the actinide series and is a synthetic, highly radioactive element with no stable isotopes.

Named after Ernest O. Lawrence, inventor of the cyclotron, Lawrencium was first synthesized at Berkeley in 1961 using particle accelerators. Memory tip: think “Lr = LawRence,” with the capital R echoing the scientist’s name, and “L for Last” to remember it caps the actinides.