) Why is Sc3+ colourless ?

1.	) Why is Sc3+ colourless ?
Answer» ANSWER: The colour obtained by D-Block i.e Transition elements is due to the presence of unpaired electrons which can let d-d transition OCCUR. However If there are no electrons or if the d-orbital is completely filled then d-d transition cannot occur and hence no colour can be obtained. In this CASE, The electronic CONFIGURATION of Scandium in ground state is [Ar] 3d1 4s2 When it's losing 3 electrons from its valence shell to form +3 cation, it's electronic configuration becomes [Ar] 3d0 4s0 which implies that it has no electrons in d-orbital to let d-d transition occur. and hence, SC3+ is colourless..

Answer»

The colour obtained by D-Block i.e Transition elements is due to the presence of unpaired electrons which can let d-d transition OCCUR.

However If there are no electrons or if the d-orbital is completely filled then d-d transition cannot occur and hence no colour can be obtained.

In this CASE, The electronic CONFIGURATION of Scandium in ground state is [Ar] 3d1 4s2

When it's losing 3 electrons from its valence shell to form +3 cation, it's electronic configuration becomes

[Ar] 3d0 4s0 which implies that it has no electrons in d-orbital to let d-d transition occur.

and hence, SC3+ is colourless..

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