No, the process of acids from plant roots breaking up rocks is not a mechanical reaction. It is a chemical reaction. Here's why:

* Mechanical reactions involve physical forces like pushing, pulling, or grinding to break down materials. Think of a hammer breaking a rock.

* Chemical reactions involve the formation or breaking of chemical bonds, resulting in the transformation of substances.

In the case of plant roots and rocks, the acids (like oxalic acid) released by the roots react chemically with the minerals in the rock, causing them to dissolve and break down. This process is called chemical weathering.

Here's a breakdown of the process:

1. Acid release: Plant roots release acids as a byproduct of their metabolism.

2. Chemical reaction: These acids react with the minerals in the rock (like calcium carbonate in limestone), dissolving them.

3. Breakdown: The dissolved minerals are then absorbed by the plant as nutrients, and the rock is gradually broken down.

So, while the outcome might appear mechanical (the rock breaking down), the underlying process is chemical.