Question

which rule was broken? drag pauli exclusion principle hunds rule aufbau principle

Explanation:

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum - numbers. In the given electron - filling diagram, two electrons in the same orbital have the same spin (both arrows pointing up), which violates the Pauli Exclusion Principle as electrons in the same orbital must have opposite spins.

Answer:

Pauli Exclusion Principle