Answer :
The reason is Diamagnetic complexes don't have unpaired electrons while paramagnetic have unpaired electrons.
What are unpaired electrons?
In chemistry, an unpaired electron is an electron that occupies an orbital of an atom singly, rather than as part of an electron pair. Each atomic orbital of an atom (specified by the three quantum numbers n, l and m) has a capacity to contain two electrons (electron pair) with opposite spins.
How do you find an unpaired electron?
For finding the number of unpaired electrons, then first we have to find the atomic number of the element then write the configuration in the ground state, then according to the oxidation state subtract the number of electrons from the outer shell. So, there are 4 unpaired electrons. So, there are 3 unpaired electrons.
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