Question

Reason of lanthanoid contraction is

• A. Neglibible screening effect of ‘f’ - orbitals
• B. Increasing nuclear charge
• C. Decreasing nuclear charge
• D. Decreasing screening effect

Answer 1

The correct option is A Neglibible screening effect of ‘f’ - orbitals

Due to poor shielding effect of 4f-orbitals, nucleus will exert a strong attraction and size of atom or ion goes on decreasing as move in the series with increase in atomic number.