Weathering is the physical disintegration and chemical decomposition of rocks to form sediments and soils.
Both mechanical and chemical weathering are responsible for the process.
Mountain ranges are worn down with time due to the action of weathering.
Rocks can be broken down over time with prolonged action of mechanical weathering via thermal expansion and contraction, alternate wetting and drying, pressure release etc.
Chemical weathering usually by the action of water dissolves rocks.
