Transition elements have a great variety of oxidation states. Identify the elements showing only three oxidation states:
A. Ni
B. V
C. Co
D. Ti
E. Fe
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, C and D only
Transition elements show many oxidation states because both the ns and the (n−1)d electrons can take part in bonding. Counting the common oxidation states of each element:
A. Ni — True. Three oxidation states.
B. V — False. Four oxidation states, up to +5 (all five 3d and 4s electrons, 3d34s2).
C. Co — True. Three oxidation states.
D. Ti — True. Three oxidation states, up to +4 (all four 3d and 4s electrons, 3d24s2).
E. Fe — False. Four oxidation states.
NCERT (2026-27 edition):
Oxidation States – “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.”
Oxidation States of the first row Transition Metal (Table 4.3)
| Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn |
|---|---|---|---|---|---|---|---|---|---|
| +3 | +2 +3 +4 | +2 +3 +4 +5 | +2 +3 +4 +5 +6 | +2 +3 +4 +5 +6 +7 | +2 +3 +4 +6 | +2 +3 +4 | +2 +3 +4 | +1 +2 | +2 |