Metal hydroxides are hydroxides of metals. They are often strong bases. They consist of hydroxide anions and metallic cations. Some metal hydroxides, such as alkali metal hydroxides, ionize completely when dissolved. Certain metal hydroxides are weak electrolytes and dissolve only partially in aqueous solution. Examples Aluminium hydroxide Beryllium hydroxide Cobalt(II) hydroxide Copper(II) hydroxide Curium hydroxide Gold(III) hydroxide Iron(II) hydroxide Mercury(II) hydroxide Nickel(II) hydroxide Tin(II) hydroxide Uranyl hydroxide Zinc hydroxide Zirconium(IV) hydroxide Lithium hydroxide Rubidium hydroxide Cesium hydroxide Sodium hydroxide Potassium hydroxide Alkali metal hydroxides Other metal hydroxides Gallium(III) hydroxide Lead(II) hydroxide Thallium(I) hydroxide Thallium(III) hydroxide Role in soils In soils, it is assumed that larger amounts of natural phenols are released from decomposing plant litter rather than from throughfall in any natural plant community. 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. References Metals Hydroxides