
Hydrogen - Wikipedia
Under standard conditions, hydrogen is a gas of diatomic molecules with the formula H2, called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is …
Hydrogen - Reactivity, Uses, Properties | Britannica
Dec 7, 2025 · One molecule of hydrogen dissociates into two atoms (H 2 → 2H) when an energy equal to or greater than the dissociation energy (i.e., the amount of energy required to break the bond that …
What is h2 in chemistry? - California Learning Resource Network
Apr 18, 2025 · Hydrogen (H 2), a diatomic molecule consisting of two hydrogen atoms covalently bonded, holds a position of paramount importance in chemistry, physics, and increasingly, in …
Hydrogen - NIST Chemistry WebBook
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of …
H2 Definition - General Biology I Key Term | Fiveable
H2 is the most abundant molecule in the universe, playing a crucial role in the formation of stars and galaxies. In biological systems, H2 is produced during metabolic processes and serves as an …
3.2: Hydrogen - The Simplest Atom - Chemistry LibreTexts
Elemental hydrogen exists as molecules each of which contains two H atoms. Pure elemental H2 under normal conditions is a colorless, odorless gas that has the lowest density of any pure substance.
Hydrogen (H) - Definition, Preparation, Properties, Uses, Compounds ...
Jan 21, 2025 · Hydrogen gas (H₂) consists of two hydrogen atoms bonded together. Each hydrogen atom has one proton in its nucleus and one electron. In the hydrogen molecule, the two atoms are …
The Element Hydrogen -- Hydrogen Atom - World of Molecules
Hydrogen is the lightest chemical element with its most common isotope consisting of just a single proton and electron. At standard temperature and pressure conditions, hydrogen forms a diatomic …
Hydrogen | H2 | CID 783 - PubChem
Molecular hydrogen (H2) is a potent free radical scavenger that not only ameliorates oxidative stress but also lowers cytokine levels. The aim of the present study was to investigate the protective effects of …
What is Hydrogen (H2) Gas? - gasdog.com
Jun 26, 2025 · Hydrogen (H2) gas is widely recognized as one of the most important elements in the universe and a potential fuel for a clean energy future. As the lightest and most abundant element, …