Radon ground state electronic configuration

Suppose that scientists were to discover a new element, one that has the chemical properties of the noble gases, and positioned directly below radon on the periodic table. Assuming that the g orbitals of the elements preceding it in the period had not yet begun to fill, what would be the atomic number and ground state electron configuration of this new element ... 

Radon, Rn At. no. 86, at. wt 222, mp—71°C, bp -61.8°C. Radon is an intermediate radioactive decay product of Ra. Rn, the most stable isotope of radon, is obtained as a gas from aqueous solutions of RaCl2 and has been used as a radiation source and as a gaseous tracer. It is a considerable hazard in uranium mines. In some areas, radon in basements and in ground water is a potential health hazard because of its radioactivity. The ground state electronic configuration of radon is [Xe]4f " 5d °6s 6p. Because radon is intensely radioactive, the chemistry of radon has only been investigated on the tracer scale. Radon forms compounds, particularly a fluoride (likely RnF2), and solid adducts between the fluoride and Lewis acid fluorides. 

The electronic ground state configurations of the gaseous actinide atoms consist of the closed-shell electronic structure of the noble gas radon, a partly filled 5/ shell, and two to four electrons in the 6d and Is states. The electronic ground state configurations for the actinides and, for comparison, the lanthanides are given in Table III. 

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