Duralumin : ${\rm{Al\;}} + {\rm{\;Cu\;}} + {\rm{\;Mg\;}} + {\rm{\;Ag}}$

German silver: ${\rm{Cu\;}} + {\rm{\;Zn\;}} + {\rm{\;C}}$

Gun metal: ${\rm{Cu\;}} + {\rm{\;Zn\;}} + {\rm{\;Sn}}$

Solder : ${\rm{Pb\;}} + {\rm{\;Al}}$

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

${\rm{H}}{{\rm{g}}_2}{\rm{C}}{{\rm{l}}_2}$

${\rm{BaS}}{{\rm{O}}_4}$

${\rm{HgC}}{{\rm{l}}_2}$

${\rm{NaHC}}{{\rm{O}}_3}$

Less

More

Equal

None of these

Tempering

Carburizing

Annealing

Nitriding

Mn

Al

W

C

All the transition elements exhibit variable oxidation states

All the transition elements form colored compounds

All the transition elements are paramagnetic

All the transition elements form complex compounds

${\rm{CuS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

${\rm{ZnS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

${\rm{CuS}}{{\rm{O}}_4}.5{{\rm{H}}_2}{\rm{O}}$

${\rm{FeS}}{{\rm{O}}_4}.7{{\rm{H}}_2}{\rm{O}}$

Sm³⁺, Eu³⁺, Gd³⁺, and Yb³⁺

Sm³⁺ and Eu³⁺ only

Gd³⁺ and Yb³⁺ only

None of these ions are paramagnetic

${\rm{H}}{{\rm{g}}^ + }$

${\rm{Hg}}_2^ +$

${\rm{Hg}}_2^{2 + }$

None of these

Yellow

White

Brown

Black