Hydrogen Elemental Symbol (H)

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

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
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

Recent Research & Development for Hydrogen

  • Jitao Lu, Liang Zhou, Qingguo Meng, Haiyan Sui, Yi Li, Xishi Tai, Self-assembly of sandwich-type (phthalocyaninato)(porphyrinato) europium double-decker complexes: Effects of hydrogen bonding on intermolecular stacking mode and morphology of self-assembled nanostructures, Dyes and Pigments, Volume 113, February 2015
  • Tushar K. Ghosh, Nisanth N. Nair, Alumina-supported Rh, Rh2, and RhI(CO) as catalysts for hydrogen evolution from water, Surface Science, Volume 632, February 2015
  • Thomas Bibienne, Volatiana Razafindramanana, Jean-Louis Bobet, Jacques Huot, Synthesis, characterization and hydrogen sorption properties of a Body Centered Cubic 42Ti–21V–37Cr alloy doped with Zr7Ni10, Journal of Alloys and Compounds, Volume 620, 25 January 2015
  • Zhewen Ma, Ding Zhu, Chaoling Wu, Chenglin Zhong, Qiannan Wang, Wanhai Zhou, Linshan Luo, Yucheng Wu, Yungui Chen, Effects of Mg on the structures and cycling properties of the LaNi3.8 hydrogen storage alloy for negative electrode in Ni/MH battery, Journal of Alloys and Compounds, Volume 620, 25 January 2015
  • Jie Dang, Guo-hua Zhang, Kuo-chih Chou, Kinetics and mechanism of hydrogen reduction of ilmenite powders, Journal of Alloys and Compounds, Volume 619, 15 January 2015
  • Jihoon Kim, Shinyoung Yeo, Jae-Deok Jeon, Seung-Yeop Kwak, Enhancement of hydrogen storage capacity and hydrostability of metal–organic frameworks (MOFs) with surface-loaded platinum nanoparticles and carbon black, Microporous and Mesoporous Materials, Volume 202, 15 January 2015
  • Agnieszka Feliczak-Guzik, Agata Wawrzynczak, Izabela Nowak, Selective catalytic oxidations of cyclohexene, thioether and geraniol with hydrogen peroxide. Sensitivity to the structure of mesoporous niobosilicates, Microporous and Mesoporous Materials, Volume 202, 15 January 2015
  • Nikhil Ranjan Pramanik, Manashi Chakraborty, Debanjana Biswal, Sudhanshu Sekhar Mandal, Saktiprosad Ghosh, Syamal Chakrabarti, William S. Sheldrick, Michael G.B. Drew, Tapan Kumar Mondal, Deblina Sarkar, Binuclear dioxomolybdenum(VI) complexes of some tridentate ONS donor ligand containing [MoO2]2+ as the acceptor center: Synthesis, crystal structure, supramolecular architectures via hydrogen bonds, p-p stacking and DFT calculations, Polyhedron, Volume 85, 8 January 2015
  • Ting Fang, Ling-Ling Zhou, Ling-Zhi Fu, Shu-Zhong Zhan, Qi-Ying Lv, Synthesis and studies of a molecular copper(I)-triazenido electrocatalyst for catalyzing hydrogen evolution from acetic acid and water, Polyhedron, Volume 85, 8 January 2015
  • Chong-he Li, Jin He, Zhao Zhang, Bo Yang, Hai-yan Leng, Xiong-gang Lu, Zhi-lin Li, Zhu Wu, Hong-bin Wang, Preparation of TiFe based alloys melted by CaO crucible and its hydrogen storage properties, Journal of Alloys and Compounds, Volume 618, 5 January 2015

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+