Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Weathering changes solid rock into sediments. Sediments are different sizes of rock particles. Boulders are sediments; so is gravel. At the other end, silt and clay are also sediments. Weathering causes rocks at the Earth's surface to change form. The new minerals that form are stable at the Earth's surface. Answer: weathering
A:
Which process causes rocks at the earth's surface to change form?