Answer:
The transition-metal have the highest oxidation number is Mo in Rb₃[MoO₃F₃]
Explanation:
Transition metals are metals that are found in the middle of the periodic table.
For the compounds:
Rb₃[MoO₃F₃]: Rb is an alkali metal that has a charge of +1. that means [MoO₃F₃] is -3. The oxyfluoride O₃F₃ has a charge of -9. That means the Mo is +6
K₄[Mn(CN)₆]: Potassium is +1, thus, the [Mn(CN)₆] is -4, As the CN is -1 and there are 6, the Mn is +2
Na[Ag(CN)₂]: As Na is +1, the [Ag(CN)₂] is -1. As CN are -1, the Ag is +1
K₂[PtCl₆]: Potassium is +1, the [PtCl₆] is -2, As the Cl are -1, the Pt is +4
[Co(NH₃)₄Cl₂]: The NH₃ are neutral, The Cl are -1, that means the Co is +2.
The transition-metal have the highest oxidation number is Mo +6
I hope it helps!