There are a few different things at play here, but generally
speaking: yes, a nucleus of ununoctium is larger than a nucleus
of Sodium, and no, the electron orbitals of Ununoctium may not
be larger than those in Sodium. On a nuclear level, protons and
neutrons do take up a finite amount of space. The size of the
nucleus is partially determined by the number of protons and
neutrons, but also by the binding energy of the nucleus (in
other words, how energetically favorable the formation of that
nucleus is). Neon atomic orbitals One measure of this is the
energy of the first excited state in the nucleus: if the first
excited state is very high in energy, it means the ground state
is very well bound, and the nucleus is probably smaller than its
nearby neighbors on the chart of the nuclides. At the atomic
(electron orbital) level, the more electrons an atom has, the
more diffuse they have to be due to charge repulsion and the
Pauli exclusion principle. However, the closure of a valence
orbital can make a huge diff