Question:
Explain lanthanide contraction clearly and give reason why many compounds of transition elements remain coloured.
Explain lanthanide contraction clearly and give reason why many compounds of transition elements remain coloured.
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Lanthanide contraction affects the properties of elements, including ionic radii and electronegativity.
Updated On: Mar 5, 2025
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Solution and Explanation
Lanthanide Contraction: A gradual decrease in atomic and ionic radii across the lanthanide series due to poor shielding by 4f electrons.
Reason for Colour: Transition elements have partially filled d-orbitals. When light falls on them, d-d transitions occur, absorbing certain wavelengths and reflecting others, giving them color.
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