Chemical stability is essential for several reasons: 1. Performance: The properties of nanomaterials often depend on their size, shape, and surface chemistry. Any change due to chemical reactions can alter their performance. 2. Safety: Unstable nanomaterials can produce toxic byproducts, posing risks to human health and the environment. 3. Durability: For applications like drug delivery and structural materials, longevity is critical. Chemically stable nanomaterials ensure prolonged efficacy and strength.