i. Manganate ion has tetrahedral structure, green colour and paramagnetic properties (due to presence of one unpaired electron). Mn in MnO42- is sp3 hybridized resulting in the tetrahedral arrangement of the four oxygen atoms around manganese. π bonds are formed due to overlap of p-orbitals of oxygen with d-orbitals of Mn.
ii. Permanganate ion has tetrahedral structure, purple colour (due to charge transfer) and diamagnetic properties [due to d0 configuration of Mn(VII)].
