CHEMISTRY COMMUNITY

Hi! I dont understand why is it more favorable for electrons in the same orbital to have oposite spins. Does it lower the orbital's potential energy?

As expressed by the Pauli exclusion principle: No two electrons in an atom can have the same set of four quantum numbers. Electron configuration simply does not allow for two electrons in the same orbital to have the same spin. When two electrons occupy one orbital, their spins must be paired. In presenting the ground-state configuration of an atom, the principles used to generate such configurations require that electrons of the same orbital be paired to maintain the lowest energy state of the atom.