When $Ag^{+}$ reacts with excess of sodium thiosulphate,the obtained species having charge and geometry respectively will be?

Match the correct option.

$A$. $[CoF_6]^{3-}$	$M$. $sp^3d^2$,paramagnetic
$B$. $[Mn(CN)_6]^{3-}$	$N$. $sp^3d^2$,diamagnetic
$C$. $[Co(C_2O_4)_3]^{3-}$	$O$. $d^2sp^3$,paramagnetic
$D$. $[Zn(H_2O)_6]^{2+}$	$P$. $d^2sp^3$,diamagnetic

Identify from the following species in which $d^2 sp^3$ hybridization is shown by the central atom:

An aqueous solution of metal ion $M1$ reacts separately with reagents $Q$ and $R$ in excess to give tetrahedral and square planar complexes,respectively. An aqueous solution of another metal ion $M2$ always forms tetrahedral complexes with these reagents. Aqueous solution of $M2$ on reaction with reagent $S$ gives a white precipitate which dissolves in excess of $S$. The reactions are summarized in the scheme given below:
$1.$ $M1$,$Q$ and $R$,respectively are :
$(A)$ $Zn^{2+}, KCN$ and $HCl$
$(B)$ $Ni^{2+}, HCl$ and $KCN$
$(C)$ $Cd^{2+}, KCN$ and $HCl$
$(D)$ $Co^{2+}, HCl$ and $KCN$
$2.$ Reagent $S$ is :
$(A)$ $K_4[Fe(CN)_6]$
$(B)$ $Na_2HPO_4$
$(C)$ $K_2CrO_4$
$(D)$ $KOH$
Give the answer for question $1$ and $2$.

Which of the following is an outer orbital complex? (Atomic numbers: $Mn = 25, Fe = 26, Co = 27, Ni = 28$)

The structure of iron pentacarbonyl,$Fe(CO)_5$,is ................. .