The element represented by the symbol "H" is hydrogen. It is the lightest and most abundant element in the universe, consisting of just one proton and one electron. Hydrogen plays a critical role in the formation of stars and is a key component of water (H2O), making it essential for life on Earth. In addition to its natural occurrence, hydrogen is used in various industrial processes, including the production of ammonia for fertilizers, refining petroleum, and in fuel cells for clean energy. Hydrogen gas is colorless, odorless, and highly flammable, presenting both advantages and challenges in its use.