Coinage metals show the properties of

In the periodic table,metals usually used as catalysts belong to:

All $Zn(II)$ compounds are white because

Which of the following pairs of substances exhibit paramagnetism among $K_2SO_4$,$MgCl_2$,$FeSO_4$,$NiCl_2$,and $ZnO$?

Although Zirconium $(Zr)$ belongs to the $4d$-transition series and Hafnium $(Hf)$ belongs to the $5d$-transition series, they show similar physical and chemical properties because . . . . . . .

In the series $Sc (Z=21)$ to $Zn (Z=30)$,the enthalpy of atomisation of zinc is the lowest,i.e.,$126 \ kJ \ mol^{-1}$. Why?