Two important classifications of weathering processes exist — physical and chemical weathering. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure. The second classification, chemical weathering, involves the direct effect of atmospheric chemicals or biologically produced chemicals (also known as biological weathering) in the breakdown of rocks, soils and minerals
Physical and chemical weathering all involve the same thing - the wearing down of an object. Physical weathering include wind and sand. Chemical weathering include corrosion and acid rain. or when you have a hammer and you bend it it is physical change.but when it rust's it's chemical change. hope it helps :)