What is Ionic radii

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Ionic radii :

The values of ionic radii of Ti²+ to Cu²+  are given below : 

Element - Ti - V - Cr - Mn - Fe 

r(M²+)(pm) - 90-88-84-80-76

The ionic radii decrease in a series due to progressive increase in the effective nuclear charge. Since the effective nuclear charge in M³+ ion is greater than the in M²+ ion, the ionic radii of transition elements decrease with increase in oxidation state, and vice versa. However , the ionic radii of transition elements are smaller than that of s-and p-block elements belonging to the same period.

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