Match List I with List II
| List I | List II |
| A. \(Cr^{3+}\) | I. \(d^3\) Configuration |
| B. \(Mn^{4+}\) | II. \(d^{10}\) Configuration |
| C. \(Cu^{+}\) | III. Paramagnetic |
| D. \(V^{2+}\) | IV. Diamagnetic |
Choose the correct answers from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-I, III; B-I, III; C-II, IV; D-I, III
The 4s electrons are removed first when a transition metal ion forms. An ion with unpaired electrons is paramagnetic; an ion with all electrons paired is diamagnetic.
A. Cr3+ — Cr (Z = 24) is [Ar] 3d5 4s1; \( \ce{Cr^{3+}} \) is [Ar] 3d3, three unpaired electrons, so paramagnetic. This matches I and III.
B. Mn4+ — Mn (Z = 25) is [Ar] 3d5 4s2; \( \ce{Mn^{4+}} \) is [Ar] 3d3, three unpaired electrons, so paramagnetic. This matches I and III.
C. Cu+ — Cu (Z = 29) is [Ar] 3d10 4s1; \( \ce{Cu^{+}} \) is [Ar] 3d10, all electrons paired, so diamagnetic. This matches II and IV.
D. V2+ — V (Z = 23) is [Ar] 3d3 4s2; \( \ce{V^{2+}} \) is [Ar] 3d3, three unpaired electrons, so paramagnetic. This matches I and III.
NCERT (2026-27 edition):
Magnetic Properties – “… Diamagnetic substances are repelled by the applied field while the paramagnetic substances are attracted. Substances which are attracted very strongly are said to be ferromagnetic. In fact, ferromagnetism is an extreme form of paramagnetism. Many of the transition metal ions are paramagnetic. Paramagnetism arises from the presence of unpaired electrons, each such electron having a magnetic moment associated with its spin angular momentum and orbital angular momentum.”