Metal hydroxide
Metal hydroxides are also known as strong bases. Many common metal hydroxides are made up from hydroxide ions and the ion of the particular metal that it is made up of. Example: When NaOH (sodium hydroxide) is dissolved in water, it forms OH ions and Na ions. Metal hydroxides ionize completely when dissolved, so that is why they are known as strong bases. Their pH is above 7, labeling them as bases. Since ions conduct electricity, metal hydroxides carry electricity very well when they are dissolved.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.
Aluminium hydroxide
Four polymorphs of aluminium hydroxide exist, all based on the common combination of one aluminium atom and three hydroxide molecules into different crystalline arrangements that determine the appearance and properties of the compound. The four combinations are:
All polymorphs are composed of layers of octahedral aluminium hydroxide units with the aluminium atom in the centre and the hydroxyl groups on the sides, with hydrogen bonds holding the layers together. The polymorphisms vary in how the layers stack together, with the arrangements of the molecules and layers determined by the acidity, presence of ions (including salt) and the surface of the minerals the substance forms on. Under most conditions, gibbsite is the most chemically stable form of aluminium hydroxide. All forms of Al(OH) crystals are hexagonal.