Question

Study the orbital diagrams of two atoms 'X' and 'Y'. Which subshell will be more stable and why?

• A. X, exchange energy is maximum, so is stability.
• B. Y, exchange energy is maximum, so is stability.
• C. X, exchange energy is minimum, so stability is maximum.
• D. Y, exchange energy is minimum, so stability is maximum.

Answer 1

The correct option is A X, exchange energy is maximum, so is stability.

Element X, have half-filled electronic configuration thus will be more stable than Y. This is due to:

1. Symmetrical distribution of electrons in all degenerated orbitals. This makes a configuration stable.

2. Exchange energy: In atom X, all are singly occupied orbital. Thus, the electrons can exchange among all five orbitals and will have high stabilisation due to high exchange energy whereas in element Y, only three orbitals have singly occupied electron with same spin and thus can show exchange behaviour/exchange energy less than X.