A hydrogen atom is the simplest and most abundant type of atom in the universe. It consists of one proton in its nucleus and one electron orbiting around it. This basic structure makes hydrogen a fundamental building block for more complex atoms and molecules. Hydrogen plays a crucial role in various chemical reactions, including those that power stars like our Sun. It is also essential for the formation of water (H2O) and organic compounds, making it vital for life on Earth. Its unique properties make hydrogen a key element in fields such as chemistry, physics, and energy production.