The correct answer is D. Rocks react with dissolved oxygen in water. This is NOT an example of mechanical weathering.
Here's a breakdown to explain each option:
A. Tree roots break apart rock: This is an example of mechanical weathering because the physical force exerted by the growing roots breaks apart the rock.
B. Acidic water dissolves limestone: This is not an example of mechanical weathering but chemical weathering. The acidic water chemically reacts with the limestone causing it to dissolve.
C. Water freezes and apart rocks: This is an example of mechanical weathering known as frost wedging. When water seeps into cracks in rocks, freezes, and expands, it exerts pressure on the rock causing it to break apart.
D. Rocks react with dissolved oxygen in water: This is not an example of mechanical weathering but a chemical reaction where rocks chemically react with dissolved oxygen in water.
Therefore, option D is the correct answer as it does not represent mechanical weathering.
