Copernicus is the answer you are looking for hope this helps!!!
Cracks in rocks : mechanical
Lichen growing on rocks : chemical
Roots or plant growth making cracks in the concrete : mechanical
Worn away statues : chemical and mechanical in my opinion
Exposed rocks : mechanical
Rust on rocks : chemical
Atlas
is the answer you are looking for ma dude
Untouchables are considered outside the caste system.
