Hydrogen is the simplest and most abundant element in the universe, represented by the symbol H on the periodic table. It consists of one proton and one electron, making it a fundamental building block for more complex elements. Hydrogen is a colorless, odorless gas at room temperature and is highly flammable. In nature, hydrogen is primarily found in compounds, such as water (H2O) and hydrocarbons. It plays a crucial role in various chemical reactions, including combustion and the formation of acids and bases. Additionally, hydrogen is being explored as a clean energy source, particularly in fuel cells and as a potential alternative to fossil fuels.