The manganate and permanganate ions are
tetrahedral, due to :
(1) The ``\pi``-bonding involves overlap of
p-orbitals of oxygen with d-orbitals of
manganese
(2) There is no ``\pi``-bonding
(3) The ``\pi``-bonding involves overlap of
p-orbitals of oxygen with p-orbitals of
manganese
(4) The ``\pi``-bonding involves overlap of
d-orbitals of oxygen with d-orbitals of
manganese