HNO₃, or nitric acid, is a strong acid commonly used in laboratories and industries. It is a colorless liquid that can appear yellow due to the presence of nitrogen dioxide. HNO₃ is highly corrosive and can cause severe burns, making it important to handle with care. It is often used in the production of fertilizers, explosives, and in the manufacturing of dyes. In addition to its industrial applications, HNO₃ plays a role in the nitrogen cycle, where it contributes to soil fertility. When it reacts with metals, it can produce nitrogen oxides, which are important for various chemical processes.