Physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water. Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.

Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.

Biological weathering is the weakening and subsequent disintegration of rock by plants, animals and microbes. … As this process continues, holes and gaps continue to develop on the rock, exposing the rock further to physical and chemical weathering.

The above explained points are all associated with weathering in all forms.