stable electron arrangement

Stability of an atom is correlated with its energy state. A stable atom generally resides in its lowest possible energy state, known as the ground state. The electrons are arranged in such a way that they fill the lowest available energy levels first, according to the Pauli's Exclusion principle and the Aufbau principle.

A stable electronic configuration means that electrons are distributed across the atomic orbitals in the most energetically favorable manner. This often corresponds to full or half-full orbitals, which are symmetric and have lower total electron-electron repulsion, thereby minimizing the overall energy of the system.