Fact 1: Chemical weathering causes iron in rock to oxidize.

Fact 2: When iron oxidizes, it rusts.

Given the two facts above, answer the question "What does chemical weathering cause iron to do?" with the following options: 
- rust
 - vomit
 - reacts
 - bruise
 - divide
 - expand
 - harm
 - burned


 

 rust        