Final answer:
Stainless steel must contain at least 10.5% chromium to be considered as such, which gives it corrosion resistance. The steel industry's evolution reflects its significance in construction, manufacturing, and the economy.
Step-by-step explanation:
The question refers to the composition of stainless steel, specifically the minimum percentage of a certain element it must contain. Stainless steel is an alloy of iron, which is refined and converted by removing impurities and adding various substances like manganese, chromium, nickel, tungsten, molybdenum, and vanadium. These elements improve the material's properties, making it suitable for a range of uses. In addition, stainless steel must contain a certain percentage of carbon, between 0.04% and 2.5%. However, the element mentioned in the question is chromium, and for steel to be considered stainless, it must contain at least 10.5% chromium. This element provides corrosion resistance, which is a defining feature of stainless steel. Today's industrial use of steel, as both a construction material and a vital component of manufacturing, underscores its importance to the economy and technological advancement.