In this task, you are given a paragraph, and your task is to construct a question from the given passage. Construct question in such a way that (i) it is well explained in the paragraph, (ii) the words may/may not be present in the paragraph, (iii) it should start with what/how/describe. Avoid creating a question that (i) is just relevant to one or two sentences, and (ii) not relevant to passage.
Q: Chemical reactions break down the bonds holding the rocks together. The rocks fall apart. They form smaller and smaller pieces. Oxidation takes place when oxygen combines with other elements in rocks. They form new types of rocks. The new substance is softer. Carbonation takes place when carbon dioxide reactions with certain types of rocks. A solution is formed that can easily be carried away by water.
A:
What happens during chemical weathering?