The d-And-f-Block Elements

Short Answer Type

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Give reasons:
Zn2+ salts are white while Cu2+ salts are blue.

Transition element exhibit colour due to d-d transition. d-d tansition is possible only when d- subshell have unpaired electron. In Cu2+ salts (3d9) d–d transition is possible. Therefore Cu2+ salts are coloured.
In Zn2+ salts (3d10) no. d–d transition is possible due to completely filled d-orbitals. Hence Zn2+ salts are white.

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