Superheavy element 114 should be a metal. Controversial data from an experiment in Dubna, Russia, suggest instead that effects from Einstein's theory of relativity might make the element's chemistry closer to that of a noble gas, like radon. If the results are confirmed, it would be the most significant departure yet from the predictable patterns in the periodic table of the elements.
Uranium (element 92, for the 92 protons in its nucleus) is the element with the highest atomic number commonly found in nature. In the lab, scientists have created additional elements up to 118 (with the exception of 117).