Question

Assertion:
Atoms with completely filled and half filled subshells are stable.

Reason:
Completely filled and half-filled subshells have the symmetrical distribution of electrons and have maximum exchange energy.

• A. Both assertion and reason are correct and reason is the correct explaination of assertion.
• B. Both assertion and reason are correct but reason is not the correct explaination of assertion.
• C. Assertion is correct but reason is incorrect.
• D. Assertion is incorrect but reason is correct.

Answer 1

The correct option is A Both assertion and reason are correct and reason is the correct explaination of assertion.

Full filled and half filled orbitals are more stable due to:-
Symmetrical distribution$\Rightarrow$More symmetry, more stability, and half filled & completely filled orbitals have symmetrical distribution.

Exchange energy:- More exchange energy, more stability and these orbitals have more number exchanges of stabilization i.e. shifting of electrons from one orbital to another within same sub-shell.