Hydrogen Elemental Symbol (H)
Hydrogen



French German Italian Portuguese Spanish Swedish
Hydrogène Wasserstoff Idrogeno Hidrogênio Hidrógeno Väte

Hydrogen Bohr ModelHydrogen is a Block S, Group 1, Period 1 element. The number of electrons in each of Hydrogen's shells is 1 and its electronic configuration is 1s1. The hydrogen atom has a radius of 37.3.pm and it's Van der Waals radius is 120.pm. In its elemental form, CAS 1333-74-0, hydrogen is a colorless, tasteless, odorless, non-metallic, non-toxic, combustible gas. Hydrogen was discovered by Sir Henry Cavendish in 1766.

Hydrogen is the first and lightest element on the periodic table and the most abundant element in the universe. As a readily refinable gas that is lighter than air, its first uses were in ballooning experiments. It was the gas used by the famous Hindenburg dirigible. It now has numerous industrial applications in oil cracking and production of other non-metallic cations, such as ammonium compounds. Deuterium (2H), an isotope of hydrogen, is used to produce heavy water (2H2O) which has application in nuclear energy production. Hydrogen can easily be generated from renewable energy sources making it a primary focus in the area of alternative energy research. Hydrogen is nonpolluting and forms water as a harmless byproduct during use. The challenges associated with the use of hydrogen as a form of energy include developing safe, compact, reliable, and cost-effective hydrogen storage and delivery technologies. Currently, hydrogen can be stored in three forms: Compressed Hydrogen, Liquid Hydrogen and Chemical Storage.

Hydrogen is highly flammable. Safety data for Hydrogen and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the safety data tab below.


  • Hydrogen Properties
  • Hydrogen Safety Data
  • Hydrogen Research
  • Hydrogen Isotopes
  • Other Elements

Hydrogen Properties


GENERAL PROPERTIES   PHYSICAL PROPERTIES  
Symbol: H Melting Point: 14.01 K, -259.14 °C, -434.45 °F
Atomic Number: 1 Boiling Point: 20.28 K, -252.87 °C, -423.17 °F
Atomic Weight: 1.00794 Density: (0 °C, 101.325 kPa 0.08988 g/L
Element Category: nonmetal Liquid Density @ Melting Point: 0.07 (0.0763 solid) g·cm−3
Group, Period, Block: 1, 1, s Specific Heat: N/A
    Heat of Vaporization 0.46 kJ mol-1
CHEMICAL STRUCTURE Heat of Fusion 0.12 kJ mol-1
Electrons: 1 Thermal Conductivity: 0.1805 W·m−1·K−1
Protons: 1 Thermal Expansion: N/A
Neutrons: 0 Electrical Resistivity: N/A
Electron Configuration: 1s1 1 Electronegativity: 2.20 (Pauling scale)
Atomic Radius: N/A Tensile Strength: N/A
Covalent Radius: 31±5 pm Molar Heat Capacity: (H2) 28.836 J·mol−1·K−1
Van der Waals radius: 120 pm Young's Modulus: N/A
Oxidation States: 1, -1 (amphoteric oxide) Shear Modulus: N/A
Phase: Gas Bulk Modulus: N/A
Crystal Structure: hexagonal Poisson Ratio: N/A
Magnetic Ordering: diamagnetic Mohs Hardness: N/A
1st Ionization Energy: 1312.0 kJ·mol−1 Vickers Hardness: N/A
2nd Ionization Energy: N/A Brinell Hardness: N/A
3rd Ionization Energy: N/A Speed of Sound: (gas, 27 °C) 1310 m·s−1
       
IDENTIFIERS   MISCELLANEOUS  
CAS Number: 1333-74-0 Abundance in typical human body, by weight: 100000000 ppb
ChemSpider ID: 4515072 Abundance in typical human body, by atom: 620000000 ppb
PubChem CID: 783 Abundance in universe, by weight: 750000000 ppb
MDL Number: MFCD00070838 Abundance in universe, by atom: 930000000 ppb
EC Number: 215-605-7 Discovered By: Henry Cavendish
Beilstein Number: N/A Discovery Date: 1766
SMILES Identifier: [H]  
InChI Identifier: InChI=1S/H Other Names: Dihydrogen
InChI Key: YZCKVEUIGOORGS-UHFFFAOYSA-N  
       
       
       
       
       


Recent Research & Development for Hydrogen

  • Bosun Jang, Taek Hyun Oh, Sejin Kwon, Effect of heat treatment of electrodes on direct borohydride-hydrogen peroxide fuel cell performance, Journal of Power Sources, Volume 268, 5 December 2014
  • Sheng-Yu Fang, Rong-Hsin Huang, Lay Gaik Teoh, Kan-Lin Hsueh, Wen-Kai Chao, Du-Cheng Tsai, Tse-Ning Yang, Fuh-Sheng Shieu, Coating TiVCr hydrogen storage alloy on the anode gas diffusion layer of proton exchange membrane fuel cells to improve performance, Journal of Power Sources, Volume 268, 5 December 2014
  • Qiong Cai, Claire S. Adjiman, Nigel P. Brandon, Optimal control strategies for hydrogen production when coupling solid oxide electrolysers with intermittent renewable energies, Journal of Power Sources, Volume 268, 5 December 2014
  • Lijie Zhang, Ming Meng, Xiaojing Wang, Shuang Zhou, Lijuan Yang, Tianyong Zhang, Lirong Zheng, Jing Zhang, Tiandou Hu, A series of copper-free ternary oxide catalysts ZnAlCex used for hydrogen production via dimethyl ether steam reforming, Journal of Power Sources, Volume 268, 5 December 2014
  • M.A. Deyab, Hydrogen generation by tin corrosion in lactic acid solution promoted by sodium perchlorate, Journal of Power Sources, Volume 268, 5 December 2014
  • Xiao-Qing Bao, Lifeng Liu, Improved photo-stability of silicon nanobelt arrays by atomic layer deposition for efficient photocatalytic hydrogen evolution, Journal of Power Sources, Volume 268, 5 December 2014
  • Yi Yu, Xiaolin Shu, Yi-Nan Liu, Guang-Hong Lu, Molecular dynamics simulation of hydrogen dissolution and diffusion in a tungsten grain boundary, Journal of Nuclear Materials, Volume 455, Issues 1–3, December 2014
  • Mancun Song, Pucheng Pei, Hongshan Zha, Huachi Xu, Water management of proton exchange membrane fuel cell based on control of hydrogen pressure drop, Journal of Power Sources, Volume 267, 1 December 2014
  • Fakhteh Siavashi, Majid Saidi, Mohammad Reza Rahimpour, Purge gas recovery of ammonia synthesis plant by integrated configuration of catalytic hydrogen-permselective membrane reactor and solid oxide fuel cell as a novel technology, Journal of Power Sources, Volume 267, 1 December 2014
  • Si-yao Guo, Song Han, Constructing a novel hierarchical 3D flower-like nano/micro titanium phosphate with efficient hydrogen evolution from water splitting, Journal of Power Sources, Volume 267, 1 December 2014
  • Tong Liu, Chunguang Chen, Fan Wang, Xingguo Li, Enhanced hydrogen storage properties of magnesium by the synergic catalytic effect of TiH1.971 and TiH1.5 nanoparticles at room temperature, Journal of Power Sources, Volume 267, 1 December 2014
  • Tong Liu, Yurong Cao, Hui Li, Wusheng Chou, Xingguo Li, Superior hydrogen storage and electrochemical properties of Mg–La–Pd trilayer films at room temperature, Journal of Power Sources, Volume 267, 1 December 2014
  • Julián Puszkiel, Fabiana C. Gennari, Pierre Arneodo Larochette, Horacio E. Troiani, Fahim Karimi, Claudio Pistidda, Rapee Gosalawit–Utke, Julian Jepsen, Torben R. Jensen, Carsten Gundlach, Martin Tolkiehn, José Bellosta von Colbe, Thomas Klassen, Martin Dornheim, Hydrogen storage in Mg–LiBH4 composites catalyzed by FeF3, Journal of Power Sources, Volume 267, 1 December 2014
  • Damien Connétable, Yu Wang, Döme Tanguy, Segregation of hydrogen to defects in nickel using first-principles calculations: The case of self-interstitials and cavities, Journal of Alloys and Compounds, Volume 614, 25 November 2014
  • Satoshi Akamaru, Masanori Hara, Masao Matsuyama, Alloying effects on the hydrogen-storage capability of Pd–TM–H (TM = Cu, Au, Pt, Ir) systems, Journal of Alloys and Compounds, Volume 614, 25 November 2014
  • M.G. Verón, F.C. Gennari, Thermodynamic behavior of the Mg–Co–H system: The effect of hydrogen cycling, Journal of Alloys and Compounds, Volume 614, 25 November 2014
  • A.V. Vyvodtceva, M.G. Shelyapina, A.F. Privalov, Yu.S. Chernyshev, D. Fruchart, 1H NMR study of hydrogen self-diffusion in ternary Ti–V–Cr alloys, Journal of Alloys and Compounds, Volume 614, 25 November 2014
  • Bao Zhang, Ying Wu, Effects of additives on the microstructure and hydrogen storage properties of the Li3N–MgH2 mixture, Journal of Alloys and Compounds, Volume 613, 15 November 2014
  • M.A. McArthur, L. Jorge, S. Coulombe, S. Omanovic, Synthesis and characterization of 3D Ni nanoparticle/carbon nanotube cathodes for hydrogen evolution in alkaline electrolyte, Journal of Power Sources, Volume 266, 15 November 2014
  • Sujuan Hu, Lichao Jia, Bo Chi, Jian Pu, Li Jian, Visible light driven (Fe, Cr)-codoped La2Ti2O7 photocatalyst for efficient photocatalytic hydrogen production, Journal of Power Sources, Volume 266, 15 November 2014


Hydrogen Isotopes


Hydrogen (H) has three naturally occurring isotopes, 1H, 2H, and 3H.

Nuclide Symbol Isotopic Mass Half-Life Nuclear Spin
1H 1.00782503207 Stable 1/2+
2H 2.0141017778 Stable 1+
3H 3.0160492777 12.32 yr 1/2+