Question

what is an example of mechanical weathering?
o the freezing and thawing of water in rock
the secretion of acids by tree roots
the exposure of limestone to acid rain
the formation of rust on iron

Explanation:

Mechanical weathering is the physical breakdown of rocks without changing their chemical composition. Freezing and thawing of water in rock (ice wedging) is a physical process. Secretion of acids by tree roots, exposure of limestone to acid rain, and rust formation on iron involve chemical changes (chemical weathering).

Answer:

the freezing and thawing of water in rock