Answer: Variable oxidation states.
- A Variable oxidation states
- B Fixed single oxidation state
- C No colour in compounds
- D Non-magnetic
Correct answer: A. Variable oxidation states
Explanation: Transition metals show multiple oxidation states because d electrons can be lost at different energies.
Aqueous solutions of transition metal ions show characteristic colours caused by electrons absorbing visible light to jump between split d-orbitals; the exact colour depends on the metal, its oxidation state, and surrounding ligands.
Concept context
Transition metals (d-block) and lanthanides/actinides (f-block). Known for coloured compounds, variable oxidation states, complex formation, and catalytic properties. Frequently tested in JEE and NEET.