Hüdrogeene

Hüdrogeene is a chemical element with the symbol H and atomic number 1. It is the lightest and most abundant element in the universe, making up about 75% of visible matter. In the cosmos it is primarily found in stars and gas giant planets, and on Earth it is a major component of water (H2O) and many organic compounds.

In its most common form, hüdrogeene exists as diatomic molecules, H2, a colorless, odorless, and highly flammable gas at room temperature. It has one electron in the first shell (1s1) and is a nonmetal. It readily forms bonds with other elements, especially oxygen to produce water, and with metals to form various hydrides. Hydrogen can participate in a wide range of oxidation states, though H2 is most stable under standard conditions.

Occurrence and production: on Earth hydrogen is present in trace amounts free in the atmosphere but is far more abundant in compounds. Industrially, hydrogen is produced mainly by steam methane reforming and, to a lesser extent, by electrolysis of water. It is also released during the refining of petroleum and in chemical processes. Storage and transport commonly use compressed gas, cryogenic liquid forms, or solid-state storage in metal hydrides.

Applications and significance: hydrogen is used in ammonia synthesis (Haber-Bosch process), petroleum refining, and as a clean fuel in fuel cells and rocket propulsion. Its energy content per unit mass is very high, but its volumetric energy density is low at ambient conditions, motivating different storage technologies.

Safety and environment: hydrogen is extremely flammable and forms explosive mixtures with air; leaks require careful handling. In energy contexts, “green” hydrogen produced from renewable electricity is contrasted with hydrogen from fossil fuels, which may involve carbon capture.