Statement $(I)$ $Co^{2+}$ has a higher magnetic moment than $Cr^{3+}$.
Statement $(II)$ Ionisation enthalpies of $Ce$,$Pr$ and $Nd$ are higher than $Th$,$Pa$ and $U$.
Which of the following is correct?

Given below are two statements:
Statement $I$: The number of pairs among $[Ti^{4+}, V^{2+}], [V^{2+}, Mn^{2+}], [Mn^{2+}, Fe^{3+}]$ and $[V^{2+}, Cr^{2+}]$ in which both ions are coloured is $3$.
Statement $II$: The number of pairs among $[La^{3+}, Yb^{2+}], [Lu^{3+}, Ce^{4+}]$ and $[Ac^{3+}, Lr^{3+}]$ ions in which both are diamagnetic is $3$.
In the light of the above statements, choose the correct option from the options given below:

Which of the following statements are correct?
$(i)$ $V^{2+}$ liberates hydrogen from a dilute acid.
$(ii)$ The earlier members of the lanthanide series behave more like aluminium.
$(iii)$ The 'silver' $UK$ coins are made of $Cu/Ni$ alloy.
$(iv)$ The maximum oxidation state exhibited by Neptunium is $+7$.

Which of the comparison regarding $Zn, Cd, Hg$ is/are incorrect?
$(I)$ $ZnCl_2$ is ionic whereas $CdCl_2$ and $HgCl_2$ are covalent
$(II)$ $Zn$ and $Cd$ dissolve in dilute acid $(HCl)$ liberating $H_2$ but $Hg$ cannot
$(III)$ $Zn$ and $Cd$ form white ppt. of $Zn(OH)_2$ and $Cd(OH)_2$ but $Hg$ forms coloured ppt. of $HgO$ or $Hg(OH)_2$
$(IV)$ All form $M_2^{2+}$ type ion

Which of the following will give a green hydrated ion?

The transition metals have a less tendency to form ions due to