Answer: can use both its 3d and 4s electrons for bonding.
- A has the smallest atomic radius in its period
- B has a fully filled 3d subshell
- C can use both its 3d and 4s electrons for bonding
- D is the most electronegative 3d metal
Correct answer: C. can use both its 3d and 4s electrons for bonding
Explanation: Mn ([Ar]3d<sup>5</sup>4s<sup>2</sup>) has five 3d and two 4s electrons all available for bonding, allowing states from +2 up to +7.
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.