The highest oxidation state in plutonium (Atomic number $=94$ ) is $+7$ . It can show a greater range of oxidation states which (in part) is attributed to the fact that $5 f, 6 d$ and $7s$ levels are of comparable energies. Plutonium (Pu) can show oxidation state of $+3,+4,+5,+6$ and $+7$ in its compound.