n=4 the fourth energy level and is designated the N shell.n=3 is the third energy level and is designated the M shell.n=2 is the second energy level and is designated the L shell.n=1 is the first energy level and is designated the K shell.The principal quantum number, n, tells us the energy level (or electron shell) that the electron is found in. You should already be familiar with the Bohr Model of the Atom which states that electrons exist in discrete energy levels (or electron shells).
No ads = no money for us = no free stuff for you! Understanding and Drawing Orbital Diagrams