Lewis structure
Electron formula ( Lewis - or Lewis formula structure Gilbert Newton Lewis) is a chemical structural formula. It is used for the preparation of atoms and molecules, which shows the structure of the molecules. Electron formula is a symbol notation, with the structure of a molecule will be described with reference to the individual atoms and valence.
Construction
In the electron formula, the element symbol is the atomic core, ie for the atomic nucleus with the inner electron shells. The one to eight bound and unbound valence electrons in the outermost electron shell of the atom are represented by dots. The electrons are distributed as four positions around the element symbol around. The brief description in the electron formula fulfills its purpose sufficiently because only the valence of the atoms are relevant for chemical reactions or chemical bonds.
By means of electron formula can be combined atoms to form molecules. With known atomic composition of small molecules can be the molecular structure of a compound to predict.
Demarcation from the valence-bond
In contrast to the valence-bond the valence electrons of the nonmetal atoms are shown individually figuratively and not together as a couple so-called valence lines.
The distinction between valence-bond electrons and formula is not uniform. In places, the term " electron formula " even used synonymously for " valence-bond ". This is also called " electron formula according to Lewis ."
As a hybrid form, there is also the notation that a stroke two outer electrons ( lone pair nonbonding electron pair ) replaced that occupy the same orbital. Points, however, symbolize individual electrons of an electron pair, which is not possible in the Valenzstrichschreibweise.