Rodrigo Fuentealba

rodrigo

Rodrigo Fuentealba

Sep 22 '21

Erik Gregersen

Encyclopedia Britannica Editor

Electrons in an atom are described by quantum numbers. The first quantum number, n, has the values 1, 2, 3, …; there is a second quantum number, l, that goes from 0 to n-1. For each set of values of n and l, there are 2l+1 distinct orbitals. From the Pauli exclusion principle, only two electrons can occupy the same orbital. The electrons fill their orbitals in order of lowest to highest (n+l), and when (n+l) is the same for two orb