Question

Sc(Z = 21) is a transition element but Zn (Z = 30) is not because :

• A. Both $S{c}^{3+}$ and $Z{n}^{2+}$ ions are colourless and form white compounds
• B. In case of $Sc,3d$ orbitals are partially filled but in $Zn$ these are filled
• C. Last electron is assumed to be added to 4s level in case of Zn
• D. Both Sc and Zn do not exhibit variable oxidation states

Answer 1

Answer: (B)

Sc $(Z=21)$ has incompletely filled $3d$-orbitals in its ground state $\left(3d^1\right)$, it is considered as a transition element but $Zn(Z=30)$ has completely filled d-orbitals $\left(3d^{10}\right)$ in its ground state and its common oxidation state of $(+2)$, it is not considered as a transition element.