Answer:
The difference is the way that each one works on rocks
Step-by-step explanation:
Chemical weathering is related principally with water and its characteristics at the moment it enters in contact with the rock, like pH, salinity and others. This type of weathering changes the chemical characteristics of the rock and ist minerals, changings its originals components. It may happen as hydrolisis, hydration, disolution and oxidation.
Physical weathering implies mechanical actions related with temperature changes and tectonic forces that may fracture the rock and make smaller and smaller, giving space to chemical weathering to keep acting on the rock until it becomes just sediment. Physical weathering can occur as gelation, minerals growth, lagging or desiccation.
There's another kind of weathering: The biological one. It is related with animals actions like making caves for living or plants growth into the rocks.