Ag

Fe

Cu

V

Washing it carefully with soap and water

Soaking it overnight in salt water

Polishing it with silver polish

Heating it gently in a fume cupboard

CuO

${\rm{A}}{{\rm{g}}_2}{\rm{O}}$

ZnO

${\rm{S}}{{\rm{b}}_2}{{\rm{O}}_3}$

$+ 2$

$+ 6$

$+ 8$

$+ 4$

Gives hardness to steel and can remove oxygen and sulphur

Helps the formation of oxides of iron

Can show highest oxidation state of +7

None of the above

They exhibit variable oxidation states.

They are all radioactive.

They are all non-reactive.

They all have full d orbitals.

In addition to the normal oxidation state, the zero oxidation state is also shown by these elements in complexes.

In the highest oxidation state, the transition metal shows basic character and form cationic complexes.

In the highest oxidation state of the first five transition elements (Sc to Mn), all the $4s$ and $4d$ electrons are used for bonding.

Once the ${d^5}$ configuration is exceeded, the tendency to involve all the $3d$ electrons in bonding decreases.

${\left[ {{\rm{Cu}}{{\left( {{\rm{N}}{{\rm{H}}_3}} \right)}_4}} \right]^{2 + }}$

${\left[ {{\rm{Ni}}{{\left( {{\rm{CN}}} \right)}_4}} \right]^{2 - }}$

${\rm{TiC}}{{\rm{l}}_4}$

${\left[ {{\rm{CoC}}{{\rm{l}}_6}} \right]^{4 - }}$

${\rm{ZnC}}{{\rm{l}}_2}$

${\rm{Zn}}{\left( {{\rm{N}}{{\rm{O}}_3}} \right)_2}$

${\left( {{\rm{C}}{{\rm{H}}_3}{\rm{COO}}} \right)_2}{\rm{Zn\;}}$

None of these

Manufacture of blue-black ink

Manufacture of chalks

Preparation of hydrogen sulphide

Preparation of sulphur dioxide

White

Green

Violet

Blue