Which weathering process is mechanical

Mechanical weathering is the physical breakdown of rock by environmental factors. This process is always at work, and there are a number of different types of mechanical weathering. Thermal expansion is the tendency for minerals to expand and contract based on temperature.

Answer:Mechanical weathering is actually breaking down of rocks into smaller pieces by natural forces. Any weathering processes that can cause the physical breakdown of rocks without any type of change in the chemical composition of rocks, called mechanical weathering.

Exfoliation: It's a process where the rocks erodes by peeling off in sheets or layer by layer rather than grain by grain.

Explanation:therefore exfoliation will match the answer to your question