Which of the following is wrongly matched?

How many of the following metal ions have similar values of spin-only magnetic moment in the gaseous state?
(Given: Atomic number: $V, 23; Cr, 24; Fe, 26; Ni, 28$)
$V^{3+}, Cr^{3+}, Fe^{2+}, Ni^{3+}$

Identify the correct statements from the following: $(i)$ $Ti(IV)$ is more stable than $Ti(III)$ and $Ti(II)$ $(ii)$ Among $3d-$series elements (from $Z=22$ to $29$) only copper has positive reduction potential $(M^{2+} / M)$ $(iii)$ Both $Sc$ and $Zn$ exhibit $+1$ oxidation state

Out of $Cu_{2}Cl_{2}$ and $CuCl_{2}$,which is more stable and why?

Fill in the blanks:
$(a)$ The ground state electronic configurations of $Cr$ and $Cu$ are .......... and ..........,respectively.
$(b)$ Transition elements exhibit certain characteristic properties due to partially filled $d$-orbitals.
$(c)$ The general electronic configuration of transition elements is .......... .

The electronic configuration of Gadolinium ($Gd$,$Z = 64$) is: