Lawrencium Shuumakumori

Element 103. Named after Ernest O. Lawrence, inventor of the cyclotron — the last actinide element. In 1961, Ghiorso's team at Berkeley synthesized it by bombarding Cf-249-252 with B-10/B-11 ions. An element that cannot exist without an accelerator, fittingly named after the accelerator's inventor. With a filled 5f shell and an anomalous 7s²7p¹ configuration, it closes the actinide series. Lr-266 half-life: ~11 hours. The "final curtain" guardian who closes the actinide gate and opens the door to transactinide superheavy elements