Which from the following series of elements is $CORRECTLY$ arranged according to their decreasing order of ionization enthalpy $(IE_1)$?

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ The atomic radii of the elements of the second transition series $(4d)$ are larger than those of the first transition series $(3d)$.
$(b)$ $Cr^{+}$,$Mn^{2+}$,and $Fe^{3+}$ have the same electronic configuration.
$(c)$ $Cr^{+}$,$Mn^{2+}$,and $Fe^{3+}$ have the same $d^5$ electronic configuration.

Transition elements act as catalysts because....

What is the highest oxidation state of third row transition elements?

$Zn$ and $Cd$ metals do not show variable valency because

The transition metal which shows oxidation states from $+2$ to $+7$ belongs to group: