Question

Which of the following is NOT a characteristic of the transition elements in the series from scandium to zinc?

• A. The formation of coloured cations
• B. The presence of at least one unpaired electron in a $d-$ orbital of a cation
• C. The ability to form complex ions
• D. The possession of an oxidation state of $+1$

Answer 1

The correct option is D The possession of an oxidation state of $+1$

The elements of the first transition series contains one or more unpaired electrons in 3d orbitals. Hence, they form coloured cations.
Due to presence of vacant inner d orbitals and small size of the cations with high charge density, the elements of first transition series have a great tendency to form complex ions.
In the transition elements series from scandium to zinc, +2 and +3 oxidation states are common. +1 oxidation state is seen only by Cr and Cu.
Hence, statement D is not a characteristic of the elements of the first transition series.