Hydrogen and Hydrogen Molecule

**Symbol:** H

**Atomic number:** 1

**International title:** hydrogen

**General formula:** H₂

**Relative Atomic Weight:** 1,008

**Information:** Hydrogen is the lightest and easiest chemical element. It is a colourless, light gas, tasteless and odourless. It is flammable but does not support fire. Hydrogen atoms are unstable and merge into two-atom molecules H₂ with a simple bond between the atoms. It is a typical non-metal.

**Use:** It has a broad practical use as a source of energy (rocket fuel), a reducing agent in chemical synthesis (synthesis of ammonia, organic synthesis) or metallurgy.

**Occurrence:** Elementary (free) hydrogen is rarely present on Earth, but it is the most widespread element in the universe. On Earth, it is predominantly found in compounds, especially water and organic compounds. It is a biogenic element.