Match List-I (feature of the oxidation states of a first row transition element) with List-II (element).
| List-I | List-II |
|---|---|
| (A) Shows all the oxidation states from +2 to +7 | (I) Scandium |
| (B) Its only oxidation state is +2, as no d electrons are involved | (II) Manganese |
| (C) Its +2 state is virtually unknown; it shows only the +3 state | (III) Copper |
| (D) Shows the +1 oxidation state besides its common +2 state | (IV) Zinc |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-II, B-IV, C-I, D-III
The oxidation states of a transition element come from its ns and (n−1)d electrons. Elements in the middle of the series show the most oxidation states; those at the two ends show fewer, because they have too few electrons to lose or too many d electrons to share.
(A) Shows all the oxidation states from +2 to +7 — This matches (II) Manganese. Mn (3d5 4s2) can use up to all seven of its 4s and 3d electrons, so it shows every state from +2 to +7, as in MnO4− (+7).
(B) Its only oxidation state is +2, as no d electrons are involved — This matches (IV) Zinc. Zn (3d10 4s2) loses only its two 4s electrons; the filled 3d10 set takes no part, so +2 is its only state.
(C) Its +2 state is virtually unknown; it shows only the +3 state — This matches (I) Scandium. Sc (3d1 4s2) has too few electrons for variety; it loses all three to form Sc3+, and scandium(II) is virtually unknown.
(D) Shows the +1 oxidation state besides its common +2 state — This matches (III) Copper. Cu (3d10 4s1) forms Cu+ (3d10) by losing its 4s electron, and its common state is +2; in Table 4.3 the +1 state is listed only for copper.
NCERT (2026-27 edition):
4.3.4 Oxidation States – “The elements which give the greatest number of oxidation states occur in or near the middle of the series. Manganese, for example, exhibits all the oxidation states from +2 to +7. The lesser number of oxidation states at the extreme ends stems from either too few electrons to lose or share (Sc, Ti) or too many d electrons (hence fewer orbitals available in which to share electrons with others) for higher valence (Cu, Zn). Thus, early in the series scandium(II) is virtually unknown and titanium (IV) is more stable than Ti(III) or Ti(II). At the other end, the only oxidation state of zinc is +2 (no d electrons are involved).”
“One of the notable features of a transition elements is the great variety of oxidation states these may show in their compounds. Table 4.3 lists the common oxidation states of the first row transition elements.”
Table 4.3: Oxidation States of the first row Transition Metal (the most common ones are in bold types)
