NH3 - NH4CL - NH4NO3 - NH3

It seems you are listing chemical compounds related to ammonia (NH3) and its derivatives or salts. Let's break down the compounds you've mentioned: 1. **NH3 (Ammonia)**: A colorless gas with a pungent smell, ammonia is a compound that consists of one nitrogen atom and three hydrogen atoms. It is widely used in fertilizers, cleaning agents, and in the production of various chemicals. 2. **NH4Cl (Ammonium Chloride)**: This is a white crystalline salt formed from the reaction of ammonia and hydrochloric acid. It is commonly used in fertilizers, as a food additive, and in some medical applications as a mucolytic agent. 3. **NH4NO3 (Ammonium Nitrate)**: It is a colorless or white crystalline solid that serves as a high-nitrogen fertilizer and is also used in explosives. It is composed of ammonium cation (NH4+) and nitrate anion (NO3−). 4. **NH3 (Ammonia)**: You have repeated ammonia at the end of your list. If you need specific information or context regarding these compounds, such as chemical reactions, uses, industrial applications, or properties, please provide more detail on what you're looking for!