The process when rocks break into smaller pieces due to exposure to natural elements is called weathering. Weathering can be physical (mechanical) where rocks are broken down into smaller pieces without chemical change, or chemical where the rock undergoes chemical alteration. Physical weathering includes processes like freeze-thaw action, root wedging, and abrasion by wind or water. Chemical weathering involves reactions with water, acids, and atmospheric gases that dissolve or change minerals in the rock.