Lawrencium is the last element of the actinide elements, a series beginning at actinium (Ac). It is a synthetic element; none occurs naturally on earth.
The element was discovered by A. Ghiorso, T. Sikkeland, A.E. Larsh, and R.M. Latimer in 1961. It was named for E.O. Lawrence, the inventor of the cyclotron.
Seaborg was associated with the discovery of many of the elements beyond uranium.
Lr is synthetic, just as are are all other elements beyond U. It was made by bombarding isotopes of californium with ions of boron--10 and boron--11. For example,
250Cf + 10B 2 1n + 258Lr
256Lr has a half-life of 28 seconds (as an alpha emitter).
Only a few atoms of Lr have ever been made, so little is known about the chemistry of the element.