Ammonia (NH₃) is a colorless gas with a distinct, pungent odor. It consists of one nitrogen atom and three hydrogen atoms, making it a simple compound. Ammonia is highly soluble in water and is commonly used in fertilizers, cleaning products, and industrial processes. In nature, ammonia is produced through the decomposition of organic matter and is a key component of the nitrogen cycle, which is essential for plant growth. It can be harmful in high concentrations, causing irritation to the eyes, skin, and respiratory system. Proper handling and safety measures are important when working with ammonia.