This document discusses different types of weathering that affect rock formations. It describes physical weathering as the breakdown of rocks through temperature fluctuations and ice formation in cracks. It also describes chemical weathering, which is more destructive, as involving chemical reactions with acids and salts that greatly alter the composition of rocks. Common agents of chemical weathering mentioned are acids, salts, and acid-bearing plants and fungi. The document lists several factors that contribute to weathering of rocks, such as erosion, decomposition, weathering, and plant and animal life. It concludes that weathering is a natural process and that rocks change over time through weathering.