What is the sole driving force behind all the exogenic processes?

What do the words volcanism and volcanoes indicate?

Why do you think that the slopes or gradients are created by tectonic factors?

Is this little motion which can occur sometimes due to weathering synonymous with transportation? If not, why?

Can we give iron rusting as an example of oxidation? How essential is water in chemical weathering processes? Can chemical weathering processes dominate in water scarce hot deserts?