Answer: 5f orbitals shield the nuclear charge even more poorly than 4f.
- A 5f orbitals are completely filled
- B actinoids experience a much smaller effective nuclear charge
- C 5f orbitals shield the nuclear charge even more poorly than 4f
- D actinoids are all diamagnetic
Correct answer: C. 5f orbitals shield the nuclear charge even more poorly than 4f
Explanation: The 5f orbitals are more diffuse and shield the increasing nuclear charge even less effectively than 4f, so the size contraction across the actinoids is more pronounced.
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.