Hydrogen compounds are chemical substances that contain hydrogen atoms bonded to other elements. These compounds can be simple, like water (H2O), where two hydrogen atoms bond with one oxygen atom, or more complex, such as hydrocarbons, which consist of hydrogen and carbon atoms. They play a crucial role in various chemical reactions and are essential in organic chemistry. Many hydrogen compounds are vital for life and industry. For example, ammonia (NH3) is a hydrogen compound used in fertilizers, while hydrogen sulfide (H2S) is known for its distinct smell and is found in natural gas. Understanding these compounds helps in fields like chemistry, biology, and environmental science.