$NH_2-NH_2$ acts as a .......

Sodium thiosulphate is used to remove the unexposed $AgBr$ from photographic films by forming a complex. In this complex of silver,the coordination number of silver is

Which of the following ligands is not bidentate?

Select the correct statements about the $PtCl_4 \cdot 4NH_3$ complex salt:
$I.$ All the chlorides are bonded by primary valency.
$II.$ All the chlorides are bonded by secondary valency.
$III.$ All the $NH_3$ are bonded by secondary valency.
$IV.$ Half of the chlorides are bonded with secondary valency.

In $Fe_{x}[Fe_{y}(CN)_6]_3$,$x$ and $y$ respectively are:

Given below are two statements :
Statement $I :$ The identification of $Ni^{2+}$ is carried out by dimethyl glyoxime in the presence of $NH_{4}OH$.
Statement $II :$ The dimethyl glyoxime is a bidentate neutral ligand.
In the light of the above statements,choose the correct answer from the options given below: