They consist of hydroxide (OH−) anions and metallic cations,[1] and are often strong bases.
Certain metal hydroxides are weak electrolytes and dissolve only partially in aqueous solution.
Many metal hydroxides are in fact complexes, i.e. molecules or ions.
The transition metal hydroxide complexes are a well developed area in coordination chemistry.
Decomposition of dead plant material causes complex organic compounds to be slowly oxidized (lignin-like humus) or to break down into simpler forms (sugars and amino sugars, aliphatic and phenolic organic acids), which are further transformed into microbial biomass (microbial humus) or are reorganized, and further oxidized, into humic assemblages (fulvic and humic acids), which bind to clay minerals and metal hydroxides.