Which element has the highest atomic number?

Oganesson has 118 protons in its nucleus, more than any other known element. It does not occur in nature and was first created in 2002 by a Russian–American team at the Joint Institute for Nuclear Research in Dubna, Russia, by firing calcium ions at a californium target. Only a handful of oganesson atoms have ever been detected, and each one decays in less than a millisecond. The element was officially named in 2016 after the Russian nuclear physicist Yuri Oganessian. It sits at the bottom of group 18 with the noble gases, although scientists predict it may behave quite differently from gases such as neon and argon.