The correct answer is Corrosion. Explanation & Key Takeaways: • There are different types of chemical weathering processes such as solution, hydration, carbonation, oxidation, reduction, and biological. • Hence corrosion is not a type of chemical weathering. Important Notes: • Chemical Weathering • It is a cluster of weathering processes namely as a solution, hydration, carbonation, oxidation, reduction, and biological. • These processes act on rocks to decompose, dissolve or moderate them to a fine clastic state through chemical reactions by oxygen, surface/ soil water, and other acids. • Water and air along with heat must be present to speed up all chemical reactions. • Solution weathering • Solution weathering occurs when the solvent is an acidic solution rather than simple water. • Hydration, • Hydration is the chemical addition of water. • Minerals take up water and enlarge. • This enlargement causes an increase in the volume of the material itself or rock. • This process is long and reversible. • This may lead to their disintegration of rocks. • Carbonation, • Carbonation is the reaction of bicarbonate and carbonate with minerals. • It is a general process that helps the fragmentation of feldspars and carbonate minerals. • Carbon dioxide from the soil and atmospheric air is absorbed by water to form carbonic acid that acts like weak acid. • These acids act on various surfaces and erode them. • Oxidation and Reduction, • In weathering, oxidation denotes the forming of a mixture of a mineral with oxygen to form hydroxides or oxides. • Oxidation happens where there is ready access to the oxygenated water. • The minerals commonly involved in this process are manganese, sulfur, iron, etc. • In the process of oxidation, rock fragmentation happens due to the disturbance caused by the addition of oxygen. • Oxidation and reduction processes are interconnected. • Biological activity and weathering • Decaying plant and animal matter help in the production of humic, carbonic, and other acids which enhance decay and solubility of some elements.