principal quantum number is considered to be the quantum number of the electron.Its value indicates the energy of the electron (e.g., a hydrogen atom or a single-electron systems).The energy of the electron is calculated as follows:

E = -13,6 / (n ^ 2) eV.

N here only accepts integer values.
Electrons can form a so-called electronic level, or electron shell, if there are many-electron levels of the electrons with the same value of n.Levels in this case, taking the value of A, B, C ... and so on, corresponding to the quantum number n = 3, 2, 1 ... The quantum value of knowing at what level the electron is not difficult.The maximum number of electrons on the level directly depends on the number n - 2 * (n ^ 2).
energy or electronic level - is a set of an electron in a stationary state.The main r
ailway quantum number indicates the distance from the nucleus.
orbital quantum number 2 can take values ​​from 0 to n-2, describing the shape of the orbitals.It also describes the sub-shell in which an electron located.Quantum number 2 has a drive letter.The quantum numbers 2 = 0, 1, 2, 3, 4 correspond to the designations 2 = s, p, d, f, g ... The alphabetical letters in the record indicating the electronic configuration of a chemical element, also present.As it is defined by the quantum number.Thus, subshell may be up to 2 * (2l + 1) electrons.
called the magnetic quantum number ml, at the same time, l appended below, as an index.His data show atomic orbital, taking the values ​​from 1 to -1.Total (21 + 1) is a value.
Electron will be a fermion, with half-integer spin, which is equal to ½.His quantum number will take two values, namely: ½ and -½.And make two projections of the electron on the axis, and read the quantum number ms.