Question

question 3. according to the diagram below, which rule is being violated?
aufbau principle
pauli exclusion principle
hunds rule
orbital notation

Explanation:

Hund's rule states that electrons must occupy degenerate orbitals (same - energy orbitals) singly before pairing up. In the given diagram, for the \(2p\) orbitals (which are degenerate), electrons should first fill each \(2p\) orbital with one electron (all with the same spin) before pairing. But here, only one \(2p\) orbital has an electron, which violates Hund's rule. The Aufbau principle is about filling orbitals from the lowest - energy to the highest - energy (\(1s<2s < 2p\), which is followed here). The Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers (in the \(1s\) orbital, the two electrons have opposite spins, so this principle is not violated). Orbital notation is just the way of representing electrons in orbitals (not a rule violation concept in the context of the question).

Answer:

Hund's rule