Question

The Lanthanoids contraction relates to:

• A. atomic radii
• B. atomic as well as $M^{3+}$ radii
• C. valence electrons
• D. oxidation states.

Answer 1

The correct option is B atomic as well as $M^{3+}$ radii

The Lanthanoids contraction relates to atomic as well as $M^{3+}$ radii.

The atomic and ionic radii ($M^{3+}$ ions) of Lanthanide elements decrease with increase in atomic number. This effect is called Lanthanoid contraction. This is due to poor shielding of 4f electrons.