Chemical tests are procedures used to identify the presence of specific substances in a sample. These tests often involve adding a reagent, which is a chemical that reacts with the target substance, producing a visible change such as a color change or precipitate. Common examples include tests for pH, glucose, and proteins. These tests are widely used in various fields, including medicine, environmental science, and food safety. They help scientists and professionals determine the composition of materials, diagnose health conditions, and ensure products meet safety standards. Accurate chemical testing is essential for informed decision-making and public health.