n
Principal quantum number Max number of e in shell = 2n2
Energy Difference = 1/n22 - 1/n12
L
L = 0 to n-1
Max # of E in subshell = 4L + 2
0, 1, 2, 3
s, p , d, f
ML
L to -L including 0
no more than 2 e-
MS
0.5 and -0.5
Electron configuration
Rank Energy shells = (n + L)