Oganesson

Oganesson is element 118, the heaviest element yet made. A Russian–American team at the Joint Institute for Nuclear Research in Dubna, with Lawrence Livermore National Laboratory, created it by firing calcium-48 nuclei at californium. The first atom was detected in 2002 and the result announced in 2006. Only about five atoms have ever been confirmed, each lasting less than a thousandth of a second.

It was named in 2016 after Yuri Oganessian, a leader in superheavy element research, making him the second living person, after Glenn Seaborg, to have an element named after him. It sits under radon with the noble gases, but calculations suggest it would be a solid, and more reactive than its lighter relatives.