Question

Valency of both scandium and aluminium is 3. How come they are in different groups?

Answer 1

Aluminium and Scandium were separated in different groups because of the atomic number . The atomic number of Aluminium is 13 and the atomic number of scandium is 21.

Answer 2

aluminium and scandium may have same valency but have different atomic no . nor there atomic mass is same . aluminium is 13 and scandium is 21 so they also have different electronic confrigution

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