The atomic sizesof Fe,Co and Ni are nearly same, Explain with reason.
Or Atomic size of 3d series elements from chromium to copper is almost the same. Give reason.

Explanation

As we move from left to right alonga transition series, the nuclear change increases which tends to decrease the size but the addition of electrons in thed-subshellincreases the screening effect which counter balances the effect of increased nuclear charge.