Hydrogen is the lightest element and the most abundant chemical substance in the universe.
Core Principles & Analysis
Henry Cavendish identified hydrogen as a distinct 'inflammable air' in 1766, and Lavoisier later named it from the Greek for 'water-former' after showing it burns to produce water.
It is the lightest element, exists as diatomic H2 gas that boils at -252.9 C, and makes up roughly three-quarters of the universe's ordinary matter by mass.
Industry consumes vast amounts of hydrogen for ammonia synthesis via the Haber-Bosch process and for petroleum refining, while liquid hydrogen fuels rockets and fuel cells power electric vehicles.