Chemistry - GENERAL CHEMISTRY Question with Solution | TestHub

The correct answer is A, B, C because all three quantum mechanical principles are violated in this electronic configuration:

The Aufbau Principle is violated because the higher-energy $2p$, $3s$, and $3p$ orbitals are being filled while the lower-energy $2s$ orbital remains incompletely filled.

Hund's Rule is violated in the $2p$ subshell because the electrons in the degenerate orbitals do not have parallel (same-direction) spins ($\uparrow ,\downarrow ,\uparrow$).

Pauli's Exclusion Principle is violated in the $3s$ orbital because it contains two electrons with identical upward spins ($\uparrow \uparrow$), which is quantum mechanically impossible.