NH3, commonly known as ammonia, 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 often used in fertilizers, cleaning products, and industrial applications due to its effectiveness as a nitrogen source. In nature, ammonia is produced through the decomposition of organic matter and is a key component of the nitrogen cycle. It can be harmful in high concentrations, causing irritation to the eyes, skin, and respiratory system. Proper handling and safety measures are essential when working with NH3.