Consider the transition metal ions Mn ³⁺, Cr ³⁺, Fe ³⁺ and Co ³⁺ and all form low spin octahedral complexes. The correct decreasing order of unpaired electrons in their respective d-orbitals of the complexes is

Step-by-step solution

For low spin octahedral complexes, electrons fill the t_ 2g orbitals first before pairing or moving to e_g orbitals. The configuration depends on the number of d-electrons. For Cr³⁺ : Electronic configuration is 3d^3 . In an octahedral field, the configuration is t_ 2g ^3 e_g^0 . Number of unpaired electrons ( n ) = 3. For Mn³⁺ : Electronic configuration is 3d^4 . For low spin, the configuration is t_ 2g ^4 e_g^0 . Number of unpaired electrons ( n ) = 2. For Fe³⁺ : Electronic configuration is 3d^5 . For low spin, t