The chemical element with the atomic number 1 is hydrogen. It is the simplest and most abundant element in the universe, consisting of just one proton and one electron. Hydrogen plays a crucial role in many chemical reactions, particularly in forming compounds like water (H2O) and organic molecules. It is also a primary fuel in stars, including the sun, through a process called nuclear fusion. Furthermore, hydrogen has various applications, including energy production through fuel cells and serving as a key component in industrial processes.