What are the valence electrons in metal

The ionic bond


Metal + non-metal ⇋ salt (ionic compound)


Octet rule

Atoms achieve an energetically optimal state when their outer shell corresponds to that of a noble gas (noble gas configuration). It is commonly referred to as an outer shell.


A metal and a non-metal react with one another because they want to fill their outer shell with electrons in order to achieve a noble gas configuration. Metals usually have 1 to 3, non-metals 4 to 7 valence electrons (outer electrons). If at least one metal and one non-metal atom react with one another, the metal releases its valence electrons to the non-metal atom. The animation shows this process using the example of the formation of table salt.

Sodium has a valence electron in its outer shell. This electron changes into the outer shell of the chlorine, which has seven outer electrons. As a result, sodium loses its 3rd shell (M-shell) and the L-shell underneath becomes the new outer shell. It is completely filled. The resulting sodium ion thus corresponds to the noble gas configuration of neon (8 outer electrons). Chlorine absorbs the electron into its outer shell and thus achieves the noble gas configuration of argon (8 outer electrons).

Charge distributions

Because the metals emit electrons and the non-metals absorb these electrons, so-called. Ions are electrically charged atoms.


Negatively charged atoms such as Cl- is called, recognizable by the appended id: Chlorineid. They contain more electrons than protons. The number of surplus electrons is shown as a superscript number with a minus attached, e.g. Cl-, O2-, P3-.


Metals give up their valence electrons. They contain more protons than electrons. Thus the positive charges predominate, the positively charged metal atom is named. The number of missing electrons is shown as a superscript number with a plus attached, e.g. Na+, Mg2+, Al3+.

Number of protons p+1117
Number of electrons e-1117
Sodium ion Chloride ion
Number of protons p+1117
Number of electrons e-1018
symbolN / A+Cl-


Magnesium + chlorine ⇋ magnesium chloride

Mg + Cl ⇋ Mg2+ + 2 cl-