The element with the atomic number one is hydrogen. Represented by the symbol "H," hydrogen is the lightest and most abundant element in the universe, making up a significant portion of stars and planets. It consists of a single proton and one electron, and it exists mainly in diatomic form (H2) under standard conditions. Hydrogen is essential for the formation of water and organic compounds, and it plays a vital role in various chemical processes, including combustion and energy production. Its versatility and abundance make hydrogen a key element in both scientific research and potential renewable energy solutions.