Configuration $=[\mathrm{Rn}] 6 \mathrm{d}^{17} \mathrm{s}^{2}$
stable oxidation state $\Rightarrow+3$
$\mathrm{Th}=+3,\,+4$
$\mathrm{Pa}=+3,\,+4,\,+5$
$U=+3,\,+4,\,+5,\,+6$