Illuminate how water affects the external 
Illuminate how water affects the external processes on the slope of Hong Kong. Explain how these external processes shape the slope landscape in Hong Kong.
Chemical weathering involves the decomposition of rock due to the alteration of rock minerals by chemical reactions between the rocks and the water with which they come into contact. Chemical reaction causes certain minerals to change into more vulnerable ones. This weakens the internal structure of the rocks, and leads to decomposition. Moisture are particularly crucial to the rate of chemical weathering. High rainfall dissolves rock minerals and weaken the rock structure.
Generally speaking, there are four main processes of chemical weathering. When we look into the impact of water on the external processes, we would have an eye to hydration and solution. Hydration refers to the absorption of water into the mineral structure, which minerals expands, turning into a new compound but a more vulnerable one. For example, calcium sulphate absorb in water to become gypsum. Besides, solution and carbonation dissolve soluble minerals in pure water or acid rain. For example, calcium carbonate in limestone is easily dissolved by carbonic acid (rainwater dissolves carbon dioxide) or acid rain ( rainwater dissolves sculpture dioxide). Calcium carbonate is then removed from the rocks in solution.
Apart from weathering, water acts on the mass movement of slope. It refers to the movement of slope material en masse downhill due the force of gravity. Slope are always under the effects of the force of gravity and the strength. The force of gravity is a stress on the materials, which tries to pull the slope materials down slope. On the contrary, strength acts against gravity in terms of the internal cohesion of slope materials and friction. It holds slope materials together and prevent slope materials from falling. When the stress exceeds the strength, the mass of slope materials will move down slope, mass movement takes
Chemical weathering involves the decomposition of rock due to the alteration of rock minerals by chemical reactions between the rocks and the water with which they come into contact. Chemical reaction causes certain minerals to change into more vulnerable ones. This weakens the internal structure of the rocks, and leads to decomposition. Moisture are particularly crucial to the rate of chemical weathering. High rainfall dissolves rock minerals and weaken the rock structure.
Generally speaking, there are four main processes of chemical weathering. When we look into the impact of water on the external processes, we would have an eye to hydration and solution. Hydration refers to the absorption of water into the mineral structure, which minerals expands, turning into a new compound but a more vulnerable one. For example, calcium sulphate absorb in water to become gypsum. Besides, solution and carbonation dissolve soluble minerals in pure water or acid rain. For example, calcium carbonate in limestone is easily dissolved by carbonic acid (rainwater dissolves carbon dioxide) or acid rain ( rainwater dissolves sculpture dioxide). Calcium carbonate is then removed from the rocks in solution.
Apart from weathering, water acts on the mass movement of slope. It refers to the movement of slope material en masse downhill due the force of gravity. Slope are always under the effects of the force of gravity and the strength. The force of gravity is a stress on the materials, which tries to pull the slope materials down slope. On the contrary, strength acts against gravity in terms of the internal cohesion of slope materials and friction. It holds slope materials together and prevent slope materials from falling. When the stress exceeds the strength, the mass of slope materials will move down slope, mass movement takes