Question

what rule is violated here? 1s 2s 2p aufbau principle hunds rule pauli exclusion principle

Explanation:

Hund's rule states that electrons will occupy degenerate orbitals singly with parallel spins before pairing up. In the given 2p - orbital diagram, electrons are paired in one 2p - orbital before filling the other 2p - orbitals singly, which violates Hund's rule. The Aufbau principle is about building up electron configurations starting from the lowest - energy orbitals, and the Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. Here, Hund's rule is the one violated.

Answer:

Hund's rule