JEE Main 2006 Chemistry question

Lanthanoid contraction is caused due to

(1)the appreciable shielding on outer electrons by 4f electrons from the nuclear charge
(2)the appreciable shielding on outer electrons by 5d electrons from the nuclear charge
(3)the same effective nuclear charge from Ce to Lu
(4)the imperfect shielding on outer electrons by 4f electrons from the nuclear chargeCorrect

Answer: (4)

Solution

The 4f orbitals are diffuse and shield the outer electrons poorly; as the nuclear charge increases across the series, the

Create a free account to read the complete working, and practise questions like this in a timed test.

Question ID VK-038830