* Mechanical weathering is the physical breakdown of rocks and minerals into smaller pieces. This can happen through processes like freezing/thawing, abrasion by wind or water, or plant roots growing into cracks.
* Leaf decay is a chemical weathering process. It involves the breakdown of organic matter (leaves) through the actions of bacteria and fungi. These organisms release acids that decompose the leaf material into simpler substances.
In summary: Mechanical weathering involves physical forces, while chemical weathering involves chemical reactions. Leaf decay is a chemical process that changes the composition of the leaves, not just their size or shape.
