Question

what is lanthanide contraction give one off .​

Answer 1

• Lanthanide contraction is the gradual decrease in the atomic and ionic size of lanthanoids with an increase in atomic number.

Causes of lanthanide contraction:

• With an increase in the atomic number, the positive charge on nucleus increases by one unit and one more electron enters same 4f subshell.

• The electrons in 4f subshell imperfectly shield each other. Shielding in a 4f subshell is lesser than in d subshell..

• With the increase in nuclear charge, the valence shell is pulled slightly towards the nucleus. This causes lanthanide contraction.