Quantum Numbers and Electron Configuration

Question 1

Aufbau Principle meaning

Answer 1

-states that electrons fill lower-energy orbitals first before moving to higher-energy orbitals.
-The order of orbital filling is: s < p < d < f.

Question 2

Pauli Exclusion Principle meaning

Answer 2

-No two electrons in an atom can have the same set of quantum numbers.
-Electrons in the same orbital must have opposite spins.

Question 3

Hund’s Rule meaning

Answer 3

-Every orbital in a sublevel is singly occupied before any orbital is doubly occupied.
-Electrons prefer to occupy empty orbitals to minimize repulsion.