reagent

A reagent is a substance used in a chemical process or experiment to detect, measure, or produce a specific reaction. It helps scientists identify the presence of particular compounds or facilitate certain chemical changes. Reagents are chosen for their ability to interact predictably with other substances, making them essential tools in laboratories for testing and analysis. For example, an indicator reagent might change color when it encounters a specific chemical, signaling its presence. In everyday terms, reagents are like specialized tools or indicators used to observe or achieve chemical transformations accurately.