The atomic size of Fe, Co and Ni are nearly same. Explain with reason.

Which set of elements have nearly the same atomic radii ?

Which series of elements would have nearly the same atomic radii ?

Explain (i) The atomic size of cerium and promethium is quite similar. (ii) Magnetic behaviour of lanthanoids. (iii) Shielding power of 4f -electrons, is quite poor.

The atomic size of cerium and promethium is. quite close, because

The oxidation state of Ni in Ni(Co)_4 is: