Question

the image below shows an orbital diagram for phosphorus.
which rule for filling orbital diagrams is violated in this diagram?
a) heisenberg uncertainty principle
b) aufbau principle
c) hunds rule
d) paul exclusion principle

Explanation:

• Heisenberg uncertainty principle: Deals with the inability to precisely know both the position and momentum of a particle simultaneously. Not related to orbital - filling rules.
• Aufbau principle: States that electrons fill orbitals starting from the lowest - energy orbitals first. The given diagram does not violate this as the lower - energy orbitals (1s, 2s, 2p, 3s) seem to be filled before 3p.
• Hund's rule: Requires that electrons fill degenerate orbitals (orbitals of the same energy, like the three 3p orbitals) one at a time with parallel spins before pairing up. In the 3p orbital section of the given diagram, electrons are paired up in one 3p orbital before filling the other 3p orbitals singly, which violates Hund's rule.
• Paul exclusion principle: States that no two electrons in an atom can have the same set of four quantum numbers. Each electron in the diagram has opposite spins (if we consider paired electrons) or unique spin - orbital combinations (for unpaired electrons in non - filled orbitals), so this rule is not violated.

Answer:

C) Hund's rule