Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in solid state?
Electronic configuration of
Ag+ - [Kr] 4d10
Cu2+ - [Ar] 3d9
Zn2+ - [Ar] 3d10
Cu+ - [Ar] 3d10 4s1
Among the four ions, only Cu2+ has an unpaired electron in the d orbital which will give rise to coloured compounds.