The number of transition metal atoms which are smaller than manganese is
 
$\text{Ti},\text{ V},\text{ Cr},\text{ Fe},\text{ Co},\text{ Ni},\text{ Cu},\text{ Zn},\text{ Tc},\text{ Ra}$

Except Ti, Zn, and Ra all the other atoms of d-block elements are smaller than Mn. Mn have larger size in first transition series due to the half-filled  $d^5$ configuration(except Sc)