The electron configuration of uranium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f3 6s2 6p6 6d1 7s2. Condensed, the standard electron configuration can be abbreviated as [Rn] 5f3 6d1 7s2 to denote only those levels with valence electrons.
Uranium is a radioactive element denoted by the chemical symbol U. It has 7 energy levels with 92 electrons, six of which are valence electrons. The element Radon (Rn) has an atomic number of 86; bracketed, Rn indicates uranium having an atomic core of 86 electrons. Energy levels depicting the valence electrons are shown as 5f3 6d1 7s2.