electrons fill the orbitals one at a time, starting with the lowest energy orbital then proceeding to the one with higher energy.
single electrons with the same spin must occupy each equal- energy orbital before additional electrons with opposite spins can occupy the same orbitals.
state that only two electrons occupy an orbital, and they must have opposite spins
Pauli Exclusion Principle
-a probability that the electron can be found in a certain volume in space around the nucleus
-this volume or region of space around the nucleus