Etiology. Cerebral palsy is relatively common, affecting 1 in 200 children. This number takes into account the full spectrum of the disorder, including milder cases, a broad definition of age of insult, and more complete case ascertainment.
Chemical weathering is the weakening and subsequent disintegration of rock by chemical reactions. These reactions include oxidation, hydrolysis, and carbonation.These processes either form or destroy minerals, thus altering the nature of the rockâs mineral composition.emperature and, especially, moisture are critical for chemical weathering; chemical weathering of rock minerals generally occurs more quickly in hot, humid climatic regions. Oxidation is the reaction of rock minerals with oxygen, thus changing the mineral composition of the rock.
Hydrolysis is the breakdown of rock to produce clay and soluble salts by acidic water. Oxidation is the breakdown of rock due to oxygen and water. Physical Weathering vs Chemical Weathering. 1  Physical weathering does not change the chemical composition of the rock whereas chemical weathering changes the composition.2  Physical weathering may result due to temperature, pressure, snow, etc. whereas chemical weathering mainly takes place due to rain.hysical Weathering vs Chemical Weathering. 1  Physical weathering does not change the chemical composition of the rock whereas chemical weathering changes the composition. 2  Physical weathering may result due to temperature, pressure, snow, etc. whereas chemical weathering mainly takes place due to rain.