The first element in the periodic table is hydrogen, which has the atomic number 1. Represented by the symbol "H," hydrogen is the simplest and most abundant element in the universe. It consists of one proton and one electron, giving it unique properties. Hydrogen plays a crucial role in various chemical reactions, including combustion and the formation of water when combined with oxygen. In addition to being a fundamental building block of matter, hydrogen is used in various applications, including fuel cells, chemical synthesis, and as a potential clean energy source in the future.