zweitwertige
Zweitwertige is a term that can refer to several distinct concepts, primarily in technical and scientific contexts. One prominent usage is in the field of chemistry, where it describes ions or compounds that possess a valency of two. This means they can form two chemical bonds or carry a charge of +2 or -2. Examples include magnesium ions (Mg^2+) and sulfide ions (S^2-). In inorganic chemistry, elements that commonly exhibit a zweitwertige state are those in Group 2 of the periodic table, like calcium and strontium, as well as transition metals such as iron in its Fe^2+ form.
In a more general sense, "zweitwertige" can be used in any situation where something has a secondary