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.

Question: Tell me about chemical weathering.
Self-contained rewrite: Tell me about chemical weathering.