Grotrian diagram

A level scheme, also level scheme or Grotrian diagram ( after its inventor Walter Grotrian ), the compilation of all energy levels is (terms) of an atom, ion, molecule or nucleus in a clear drawing representation.

Construction

On the ordinate (Y -axis), the main and secondary bowls of the system are plotted as energy platforms and on the abscissa the number of electrons. The main shells are counted starting from the core away from 1 ( alternatively, the trays may also be referred to with capitals). The highest shell of an energy level diagram corresponding to the period of the respective element. Each atom case has its own electron configuration. The further a tray is removed from the core, the higher the energy level of an electron, which is located thereon.

The level scheme is only for a very simple system with only one electron by a single " ladder " represented. In more complex systems, several ladders must be in or next to each other.

Regulate

The energies of the individual terms are scaled so applied as horizontal lines that the lowest energy or ground state representative line is furthest below. When filling orbitals of the Hund's rule is followed, according to the number of orbitals with the same energy only to be occupied with electrons of the same spin before electrons are distributed with opposite spin.

Atoms whose last occupied electron is located on the P- level and have a fully staffed S- and P- shell belong to the noble gases. Atoms, which have their outer electrons on the 4f level, belong to the group of lanthanides, whereas they are at 5f actinides.

Transitions

During a transition from a higher to a lower expression of the distance between the starting and the final term corresponds to the energy of the emitted photon; This process therefore produces a corresponding spectral line. There are, however, not allow all transitions, some are banned from quantum-mechanical reasons and are therefore not observed in the spectrum (see selection rules ).