Stainless steel is a type of steel that contains at least 10.5% chromium by mass. The presence of chromium in stainless steel is what makes it highly resistant to rust and corrosion. When stainless steel is exposed to oxygen, a thin layer of chromium oxide forms on the surface. This layer is highly stable and non-reactive, which means that it does not react with water or other elements in the environment that can cause rust and corrosion. In addition to chromium, stainless steel may also contain other elements, such as nickel, molybdenum, and nitrogen, which can further improve its resistance to rust and corrosion. The presence of chromium oxide on the surface of stainless steel is what makes it highly resistant to rust and corrosion, making it a popular material for use in a wide range of applications. These applications including kitchen appliances, medical equipment, and industrial machinery.