**Introduction**
Electrons are the fundamental particles that occupy the orbitals around the nucleus of an atom. The stability of an atom is determined by the electronic configuration of its valence shell. Half-filled and fully filled electronic configurations are considered more stable than other configurations. This stability is due to the following reasons:

**Exchange Energy**
Exchange energy is the energy associated with the exchange of positions between two electrons. When two electrons occupy the same orbital, they repel each other. When the electrons occupy different orbitals, the energy associated with the exchange of positions between them is reduced. In half-filled and fully filled electronic configurations, the electrons occupy different orbitals, and the exchange energy is minimized. As a result, these configurations are more stable.

**Electron Repulsion**
Electron repulsion is the force that arises from the interaction between electrons. When two electrons occupy the same orbital, they repel each other, and this repulsion destabilizes the atom. In half-filled and fully filled electronic configurations, the electrons occupy different orbitals, and the electron repulsion is minimized. As a result, these configurations are more stable.

**Pauli Exclusion Principle**
Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. In other words, each electron must occupy a different orbital. In half-filled and fully filled electronic configurations, the electrons occupy different orbitals, and the Pauli exclusion principle is satisfied. As a result, these configurations are more stable.

**Hund's Rule**
Hund's rule states that when orbitals of equal energy are available, electrons will occupy them singly before they pair up. In other words, electrons will occupy different orbitals before they start pairing up. In half-filled and fully filled electronic configurations, the electrons occupy different orbitals, and Hund's rule is satisfied. As a result, these configurations are more stable.

**Conclusion**
In conclusion, half-filled and fully filled electronic configurations are more stable than other configurations due to the minimized exchange energy, minimized electron repulsion, satisfaction of the Pauli exclusion principle, and the satisfaction of Hund's rule. These stable electronic configurations play an important role in the chemical behavior of elements and their compounds.

Due to:-1)Symmetrical distribution:- more the symmetrical distribution more the stability. The half filled and full filled orbitals are more stable due to their symmetrical distribution....2)stability due to due to exchange energy:- the half filled and full filled degenerate orbitals have more no. of exchanges and consequently , have large exchanges of stabilisation.the exchange means shifting of electrons from one orbital to another within same sub-shell.