The element with the atomic number 1 is hydrogen. It is the simplest and lightest element in the periodic table, consisting of just one proton and one electron. Hydrogen is a fundamental building block of the universe, playing a crucial role in the formation of stars and galaxies. It is also essential for life, as it is a component of water and organic compounds. Hydrogen exists in various forms, such as diatomic hydrogen (H₂), which is the most common form found in nature. This versatility makes hydrogen significant in fields like chemistry, energy production, and biology.