Question

1. What is the result of a rock undergoing physical weathering?

Answer 1

1. The answer is; soil.  When rock weathers, it disintegrates into small and smaller particles. When these fine rocks particles combine with organic matter from living organisms, they make soil. The mineral component of the soil is therefore similar to that of the parent rock from which it came from.

2. Chemical weathering involves the reaction of the rock mineral with ‘chemicals’ or other compounds. These may include reaction with organic acids or acidic rainwater.  Due to the chemical reaction, the rock chemical composition changes and the physical appearance may also look different.

3. The answer is limestone rocks. They are made of carbon-carbonate minerals. Carbon carbonate is easily dissolved by acids include slightly acidic rainwater/ precipitation.        

CO2 + H2O → H2CO3 (carbon dioxide + water → carbonic acid)

H2CO3 + CaCO3 → Ca(HCO3)2 (carbonic acid + calcium carbonate → calcium bicarbonate)

4. Weathering of rocks is slower in cold regions than dry regions. This is because cold places do not encourage chemical weathering. Chemical weathering requires higher temperatures to  increase the energies of the chemical atoms so that they react fast.