CBSE 2026 · Region 2 · Set 2 · Q19 · 2 marks
(a)Why is third ionization enthalpy of manganese very high ? $\displaystyle 1$ + $\displaystyle 1$(b)Why Zn, Cd and Hg are not regarded as transition elements ?
(a)
Why is third ionization enthalpy of manganese very high ? $\displaystyle 1$ + $\displaystyle 1$
(b)
Why Zn, Cd and Hg are not regarded as transition elements ?
Marking-scheme solution
(a)
Mn2+ = [Ar] 3d54s0. It has a stable half- filled configuration hence energy
required to remove third electron is very high.
(b)
Because they have completely filled d orbitals in their ground state as well as
in common oxidation state.
The d-and f-Block ElementsGeneral Properties of the Transition Elements (d-Block)Understandvery_short_answermedium
More from The d-and f-Block Elements
- (i) Silver atom has completely filled d-orbitals in its ground state, it is still considered to be a…2022 · asked 3×
- (i) Describe giving reason which one of the following pairs has the property indicated: (I) Fe or Cu - higher…2026 · asked 3×
- The diamagnetic species is:2025 · asked 3×
- Assertion: Zr and Hf are of almost similar atomic radii. Reason (R): This is due to Lanthanoid contraction.2024 · asked 3×
- (i) When pyrolusite ore is fused with KOH, in presence of air, a dark green coloured product 'A' is obtained…2025 · asked 3×
- The element having [Ar] 3 d^10 4 s^1 electronic configuration is2025 · asked 3×
- From the given E^ values of the first row transition elements, answer the following questions: (i) Why is E…2022 · asked 3×
- Account for the following: (i) Transition metals and their compounds show catalytic activities. (ii) Zn, Cd…2022 · asked 3×
CBSE Class 12 Chemistry past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.