Question

Which transition element of the 3d series does not show variable oxidation state?

• A. Scandium (Sc)
• B. Titanium (Ti)
• C. Zinc (Zn)
• D. Chromium (Cr)

Hint:

Remember the common oxidation states of the first transition series: \[ \boxed{ \begin{aligned} Sc &\rightarrow +3\\ Ti &\rightarrow +2,\,+3,\,+4\\ V &\rightarrow +2\text{ to }+5\\ Cr &\rightarrow +2,\,+3,\,+6\\ Mn &\rightarrow +2\text{ to }+7 \end{aligned} } \] Scandium is the only transition element of the 3d series that predominantly shows only one oxidation state (\(+3\)).

Answer 1

The Correct Option is A

Among the 3d transition elements, Scandium (Sc, $[Ar]3d^14s^2$) exhibits only the $+3$ oxidation state because losing all three valence electrons gives it an empty 3d subshell, and Zinc (Zn, $[Ar]3d^{10}4s^2$) shows only $+2$ because its completely filled $3d^{10}$ is energetically stable and not available for bonding. Both elements lack the variable oxidation states characteristic of most other transition metals.