Hydrogen

Definition

Hydrogen is a chemical element; it has the symbol H and atomic number 1. It is the lightest and most abundant chemical element in the universe, constituting about 75% of all normal matter. 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 colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas H2 (dihydrogen) and in molecules, such as in water and organic compounds. The most common isotope of hydrogen, 1H, consists of one proton, one electron, and no neutrons.

Related concepts

1000000000 (number)2001 Mars Odyssey Abundance of the chemical elements Acid Acid–base reaction Actinium Activated carbon Active site Airship Alkali earth metals Alkali metal Alkaline earth metal Alkaline earth metals Alkene Alkyne Alternative fuel vehicle Aluminium Aluminium hydride American Institute of Chemical Engineers Americium Ammonia Ammonia borane Ammonia production Amorphous carbon Amorphous metal Amorphous silicon Ancient Greek language Angular momentum Anion Anode Anoxic waters Antihydrogen Antimatter Antimony Antimuon Antioxidant Antiproton Antoine Lavoisier Aqueous solution Argon Argon fluorohydride Arsenic Arsenic acid Arsenous acid Astatine Atmosphere (unit)Atmospheric escape Atmospheric pressure Atomic hydrogen welding Atomic nucleus Atomic number Australia Autoignition temperature Balloon Balmer series Barium Baryon Base pair Battery electric vehicles Berkelium Beryllium Beta decay Beta minus decay Beta radiation Big Bang baryogenesis Big Bang nucleosynthesis Biohydrogen Bioreactor Bismuth Blimp Block (periodic table)Bohr model Bohrium Boiling point Bond dissociation energy Borane Boron Boron group Brian Wirth Bridging ligand Brine Bromic acid Bromine Bromous acid Brønsted–Lowry acids Brønsted–Lowry acid–base theory CANDU reactor CAS Registry Number CNO cycle CRC Handbook of Chemistry and Physics CRC Press Cadmium Caesium Calcium Californium Cambridge University Press Carbon Carbon Brief Carbon capture and storage Carbon group Carbon monoxide Carbonic acid Catalyst Cathode Cation Ceria based thermochemical cycles Cerium Chain reaction Chalcogen Chemical bond Chemical compound Chemical element Chemical formula Chemical reaction Chemical symbol Chlamydomonas reinhardtii Chloric acid Chlorine Chloroauric acid Chloroosmic acid Chloroplast Chloroplatinic acid Chlorous acid Chromic acid Chromium Chronology of the universe Cobalt Cobalt tetracarbonyl hydride Coke (fuel)Columbia University Combined cycle hydrogen power plant Combustible Commission on Isotopic Abundances and Atomic Weights Computers & Chemical Engineering Coolant Copernicium Copper Copper–chlorine cycle Cosmic ray Cosmic rays Covalent bond Covalent bonding Covalent radius Critical point (thermodynamics)Critical temperature Cryogenic Cryogenic propellant Crystal lattice Crystal structure Curium Cyanobacteria D-block Damped Lyman-alpha system Dark reaction Darmstadtium Dayton, Ohio De Rivaz engine Decay product Density Detonation Deuterium Diamagnetic Diatomic Diatomic molecule Diethyl ether Dihydrogen complex Diproton Dirac equation Disulfuric acid Dithionic acid Dopant (semiconductor)Dubnium Dynamic viscosity Dysprosium Döbereiner's lamp E number Early universe Edward Daniel Clarke Eigenvalue Einsteinium Electric arc furnace Electrodes Electrolysis Electrolysis of water Electrolyte Electrolyzer Electron Electron configuration Electron donor Electronegative Electronegativity Electronvolts Electropositive Electrostatic attraction Encyclopædia Britannica Energy Research & Social Science Energy level Enthalpy of combustion Enthalpy of fusion Enthalpy of vaporization Erbium Ernest Rutherford Ethane European Union Europium Excited state Exothermic Exotic atom Extreme pressure F-block Fayalite Ferdinand von Zeppelin Fermentation Fermium Ferric oxide Ferrous ion Fertilizer Flame detector Flerovium Fluorine Fluoroboric acid Fluorosulfuric acid Food additive Forming gas Fossil fuel Fossil fuels France Francium Frank P. Incropera François Isaac de Rivaz Fuel cell Fuel cells Fugitive gas emissions Fulminic acid GHS hazard pictograms GHS hazard statements GHS precautionary statements Gadolinium Gallium Gas Gas giant Gas venting Genetic code Genetically modify Germanium Germany Giant planet Gilbert N. Lewis Globally Harmonized System of Classification and Labelling of Chemicals Gold Gravity Greece Green ammonia Green hydrogen Green methanol Ground state Groundwater Group (periodic table)Group 10 element Group 11 element Group 12 element Group 1 elements Group 2 elements Group 3 element Group 4 element Group 5 element Group 6 element Group 7 element Group 8 element Group 9 element H2+HCl H II region Haber process Hafnium Half-life Halogen Harold Urey Hassium Heavy water Helium Helium-3 Henri Giffard Henry Cavendish Heteroatom Hexafluorosilicic acid Hexafluorozirconic acid Hexagonal crystal system Hindenburg-class airship Hindenburg disaster History of atomic theory Holmium Hubble Space Telescope Human gut flora Hybrid sulfur cycle Hydride Hydride anion Hydrocarbon Hydrochloric acid Hydrocracking Hydrodesulfurization Hydrogen-cooled turbogenerator Hydrogen (disambiguation)Hydrogen astatide Hydrogen atom Hydrogen bomb Hydrogen bond Hydrogen bonding Hydrogen breath test Hydrogen bromide Hydrogen chloride Hydrogen compounds Hydrogen cyanide Hydrogen cycle Hydrogen disulfide Hydrogen economy Hydrogen electrolyzer Hydrogen embrittlement Hydrogen fluoride Hydrogen iodide Hydrogen isocyanide Hydrogen leak Hydrogen line Hydrogen peroxide Hydrogen production Hydrogen safety Hydrogen selenide Hydrogen spectral series Hydrogen sulfide Hydrogen technologies Hydrogen telluride Hydrogen transport Hydrogenase Hydrogenation Hydrogenolysis Hydron Hydronium HyperPhysics Hyperfine structure Hypobromous acid Hypochlorous acid Hypofluorous acid Hypoiodous acid Hyponitrous acid Hypophosphorous acid IPCC IPCC Sixth Assessment Report IRENA IUPAC IUPAC nomenclature Inch of mercury Indium Inert gas asphyxiation Inorganic Chemistry (journal)Intergalactic medium International Energy Agency International Space Station International Union of Pure and Applied Chemistry Interstellar medium Iodic acid Iodine Iodous acid Ionic bonding Ionic compounds Ionic hydrides Ionization energy Ionized Iridium Iron Iron filings Iron oxide Iron oxide cycle Iron–nickel alloy Isocyanic acid Isothiocyanic acid Isotope geochemistry Isotope of hydrogen Isotopes of hydrogen Jacques Charles James Clerk Maxwell James Dewar Japan John A. Peacock Joule per mole Journal of Biomolecular NMR Jupiter Keith Olive Kelvin Kilojoule per mole Kilojoules Kinematic viscosity Kinetic isotope effect Krypton LZ 129 Hindenburg Lanthanum Lattice constant Lawrence Berkeley National Laboratory Lawrencium Lead Leak detection Lifting gas Ligand Light-dependent reactions Limelight Liquefaction Liquid-propellant rocket Liquid hydrogen Liquid oxygen List of atomic weights List of chemical element name etymologies List of data references for chemical elements Literal translation Lithium Lithium aluminium hydride Lithium hydride Livermorium Logarithmic scale Lone pair Long-Qing Chen Lutetium Magnesium Magnetic susceptibility Magnetism Mali Manganese Manganic acid Margarine Mark Oliphant Mars Global Surveyor Mass Mass conservation Megahertz Megajoules Meitnerium Melting point Mendelevium Mercury (element)Metal-acid reaction Metal hydride Metallic hydrogen Methane Methane pyrolysis Methanol Metre per second MgO Mildred Dresselhaus Molar heat capacity Mole (unit)Molecular cloud Molecular weight Molecule Molybdenum Molybdic acid Moscovium Muonium Mycobacterium smegmatis N-type semiconductor NASA NFPA 704 NGC 604 NMR spectroscopy NOx Nanometer National Academies Press National Institute of Standards and Technology Natural abundance Natural gas Natural hydrogen Neodymium Neon Neptunium Neutron Neutron diffraction Neutron moderator New Jersey New York City Nickel Nickel–hydrogen battery Nihonium Niobium Nitric acid Nitrogen Nitrosylsulfuric acid Nitrous acid Nitroxyl Nobelium Noble gas Nonmetallic Norman Greenwood Nuclear fuel rod Nuclear fusion Nuclear isomer Nuclear reactor Nuclear weapons tests Nucleosynthesis Nuclide Oganesson Olefin Ore Organic compound Osmium Oxidation Oxidation state Oxidize Oxonium ion Oxygen P-block PH Palladium Particle Data Group Parts per million Pascal (unit)Passivation (chemistry)Paul Harteck Pearson symbol Pentaoxidane Perbromic acid Perchloric acid Period (periodic table)Period 1 element Period 2 element Period 3 element Period 4 element Period 5 element Period 6 element Period 7 element Periodic acid Periodic table Permanganic acid Peroxydisulfuric acid Peroxymonosulfuric acid Petroleum cracking Phase (matter)Phase diagram Phlogiston theory Phosphoric acid Phosphorous acid Phosphors Phosphorus Photon Photosynthetic Physical Review D Physical cosmology Picometre Pierre-Simon Laplace Plasma (physics)Plasma state Platinum Plutonium Pnictogen Polonium Polonium hydride Positron Potassium Pound per square inch Prandtl Number Praseodymium Pressure swing adsorption Primary atmosphere Primordial nuclide Progress in Materials Science Promethium Propane Properties of water Protactinium Protein folding Proton Proton-proton reaction Protonated molecular hydrogen Pure Appl. Chem.Pure and Applied Chemistry Pyrolysis Pyrophosphoric acid Quantization (physics)Quantum effects Quantum mechanics Quantum number R34 (airship)Radioactive decay Radiolabel Radioluminescent paint Radium Radon Rare earths Recombination (cosmology)Redshift Reducing agent Reducing soil Reduction (chemistry)Regenerative cooling Reionization Relativistic quantum mechanics Rhenium Rhodium Rigid airship Robert Boyle Rocket propellant Rocky Mountain Institute Roentgenium Romanization of Ancient Greek Room temperature Rotational energy levels Rotational–vibrational spectroscopy Rubidium Ruthenium Rutherfordium S-block Samarium Saturated and unsaturated compounds Scandium Schikorr reaction Schrödinger equation Science (journal)Seaborgium Selenic acid Selenium Selenous acid Self-energy Self-powered lighting Semiconductor manufacturing Serpentinization Shielding gas Silicic acid Silicon Silver Singlet state Slush hydrogen Sodium Sodium bicarbonate Sodium hydride Solid hydrogen Solubility Space Shuttle Main Engine Space Shuttle main engines Specific heat Specific heat capacity Spectral line Speed of sound Spin (physics)Spin isomers of hydrogen Stable isotope Standard atomic weight Standard conditions Standard pressure Standard temperature and pressure Star Star formation Steam Steam methane reforming Steam reforming Steel Steelmaking Stoichiometric Strontium Strömgren sphere Sulfamic acid Sulfur Sulfuric acid Sulfurous acid Sulfur–iodine cycle Sun Superconductivity Sweetening (fossil fuels)Syngas Synthesis gas Synthetic fuel Tantalum Technetium Technical University of Denmark Telluric acid Tellurium Tellurous acid Tennessine Terbium Tetrahydroquinoline Tetraoxidane Thallium The Hype about Hydrogen The Periodic Table of Videos Thermal conductivity Thermal diffusivity Thiocarbonic acid Thiocyanic acid Thiosulfuric acid Thorium Thulium Timeline of chemical element discoveries Timeline of hydrogen technologies Tin Titanic acid Titanium Tonne Total molecular spin Trace radioisotope Tracer gas Transducers Transition metal Triangulum Galaxy Triatomic hydrogen Triflic acid Trihydrogen cation Trihydrogen oxide Trioxidane Triphosphoric acid Triple point Triplet state Tritium Tritium radioluminescence Tungsten US Eastern seaboard Ultraviolet United States Unsaturated fat Uranium Vacuum flask Vacuum polarization Van der Waals radius Vanadium Vapor pressure Variable renewable electricity Vegetable oil Viscosity Volumetric ratio Water Water gas shift reaction Water splitting Water table Weather balloon Weight percent Welding Xenon Yale Environment 360 Ytterbium Yttrium Zeppelin Zinc Zinc–zinc oxide cycle Zirconium Zirconium cladding ZnO

41 concepts already in your glossary