The Quantum Numbers The quantum mechanical model of the atom explains that the electrons surrounding the nucleus exist in the form of electron clouds called Orbitals_There are four quantum numbers of an atom. The principal quantum number represents the energy level of an atom. It has a symbol of n . If the electron configuration ends in 2s', then the value of n is | The azimuthal quantum number (1) describes the of the orbital to which the electron belongs. S orbital has azimuthal value (1) of 0, p orbital is d orbital 2 and f orbital, ____. The (mi) describes the orientation of an electron in a magnetic field. Sublevel p has ml values of -1, and +1. The electron spin quantum number (ms) specifies how electron spins or rotates. It can be expressed in two values:_____and_____​