Conversation so far:
What is weathering?
Weathering is the breaking down of rocks, soil, and minerals as well as wood and artificial materials through contact with the Earth's atmosphere, water, and biological organisms.
What are its major types of weathering ?
There are four main types of weathering. These are freeze-thaw, onion skin (exfoliation), chemical and biological weathering. Most rocks are very hard.
Tell me about chemical weathering.
Chemical weathering is the process by which rocks are broken down by chemical reactions. ... When iron in rocks reacts with oxygen, it forms iron oxide, which weakens the rock.
How is chemical weathering different from biological weathering?
Biological weathering is weathering caused by plants and animals. Plants and animals release acid forming chemicals that cause weathering and also contribute to the breaking down of rocks and landforms.

Question: Does it change the composition of rocks?
Self-contained rewrite: Does weathering change the composition of rocks?