What is the electron configuration by shells for the elements phosphorus?

Phosphorous has 15 electrons, so its configuration is:

1s2, 2s2, 2p6, 3s2 3p3,



n=1 shell has 2 (s) electrons

n=2 shell has 8 (2s and 6p) electrons

n=3 shell has 5 (2s and 3p) electrons