Hydrogen Elemental Symbol (H)
Hydrogen



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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

  • TiO2 Single Crystal with Four-Truncated-Bipyramid Morphology as an Efficient Photocatalyst for Hydrogen Production. Zhang K, Liu Q, Wang H, Zhang R, Wu C, Gong JR. Small. 2013 Jun 19. doi: 10.1002/smll.201300841. [Epub ahead of print]
  • Cobalt-Catalyzed Hydrosilation/Hydrogen-Transfer Cascade Reaction: A New Route to Silyl Enol Ethers. Lyons TW, Brookhart M. Chemistry. 2013 Jun 18. doi: 10.1002/chem.201301502. [Epub ahead of print]
  • Significantly enhanced photocatalytic hydrogen evolution under visible light over CdS embedded on metal-organic frameworks. He J, Yan Z, Wang J, Xie J, Jiang L, Shi Y, Yuan F, Yu F, Sun Y. Chem Commun (Camb). 2013 Jun 19. [Epub ahead of print]
  • OxyR, an important oxidative stress regulator to phenazines production and hydrogen peroxide resistance in Pseudomonas chlororaphis GP72. Xie K, Peng H, Hu H, Wang W, Zhang X. Microbiol Res. 2013 Jun 15. doi:pii: S0944-5013(13)00084-0. 10.1016/j.micres.2013.05.001. [Epub ahead of print]
  • The study of pH-dependent stability shows that TPLH-mediated hydrogen-bonding network is important for the conformation and stability of human gankyrin. Yuan C, Guo Y, Zhu L, Guo W, Mahajan A, Weghorst CM, Li J. Biochemistry. 2013 Jun 18. [Epub ahead of print]
  • Contradictory Effects of Superoxide and Hydrogen Peroxide on KCa3.1 in Human Endothelial Cells. Choi S, Na HY, Kim JA, Cho SE, Suh SH. Korean J Physiol Pharmacol. 2013 Jun;17(3):181-7. doi: 10.4196/kjpp.2013.17.3.181. Epub 2013 Jun 11.
  • Identification of a second Nutlin-3 responsive interaction site in the N-terminal domain of MDM2 using hydrogen/deuterium exchange mass spectrometry. Hernychova L, Man P, Verma C, Nicholson J, Sharma CA, Ruckova E, Teo JY, Ball K, Vojtesek B, Hupp TR. Proteomics. 2013 Jun 17. doi: 10.1002/pmic.201300029. [Epub ahead of print]
  • Unusual Folding Propensity of an Unsubstituted ß,?-Hybrid Model Peptide: Importance of the C?H···O Intramolecular Hydrogen Bond. Venugopalan P, Kishore R. Chemistry. 2013 Jun 17. doi: 10.1002/chem.201300630. [Epub ahead of print]
  • Alleviation of chromium toxicity by hydrogen sulfide in barley. Ali S, Farooq MA, Hussain S, Yasmeen T, Abbasi GH, Zhang G. Environ Toxicol Chem. 2013 Jun 17. doi: 10.1002/etc.2309. [Epub ahead of print]
  • Ternary Ti-Mo-Ni mixed oxide nanotube arrays as photoanode materials for efficient solar hydrogen production. Allam NK, Deyab NM, Abdel Ghany N. Phys Chem Chem Phys. 2013 Jun 17. [Epub ahead of print]
  • [A new methods for determining hydrogen sulfide release in cultured cells]. Xie J, Zeng Q, Zheng Y, Liao F, Xu GH, Tang CS, Geng B. Beijing Da Xue Xue Bao. 2013 Jun 18;45(3):489-92. Chinese.
  • The origin of enantioselectivity in the l-threonine-derived phosphine-sulfonamide catalyzed aza-Morita-Baylis-Hillman reaction: effects of the intramolecular hydrogen bonding. Lee R, Zhong F, Zheng B, Meng Y, Lu Y, Huang KW. Org Biomol Chem. 2013 Jun 17. [Epub ahead of print]
  • Determining hydrogen-bond interactions in spider silk with 1H-13C HETCOR fast MAS solid-state NMR and DFT proton chemical shift calculations. Holland GP, Mou Q, Yarger JL. Chem Commun (Camb). 2013 Jun 17. [Epub ahead of print]
  • Multidimensional modeling of biofilm development and fluid dynamics in a hydrogen-based, membrane biofilm reactor (MBfR). Martin KJ, Picioreanu C, Nerenberg R. Water Res. 2013 May 9;47(13):4739-4751. doi: 10.1016/j.watres.2013.04.031. [Epub ahead of print]
  • Protective effects of hydrogen-rich saline on ulcerative colitis rat model. He J, Xiong S, Zhang J, Wang J, Sun A, Mei X, Sun X, Zhang C, Wang Q. J Surg Res. 2013 Jun 5. doi:pii: S0022-4804(13)00495-2. 10.1016/j.jss.2013.05.047. [Epub ahead of print]
  • Cholesterol accelerates the binding of Alzheimer's ß-amyloid peptide to ganglioside GM1 through a universal hydrogen-bond-dependent sterol tuning of glycolipid conformation. Fantini J, Yahi N, Garmy N. Front Physiol. 2013 Jun 10;4:120. doi: 10.3389/fphys.2013.00120. Print 2013.
  • Association between Symptoms of Irritable Bowel Syndrome and Methane and Hydrogen on Lactulose Breath Test. Lee KN, Lee OY, Koh DH, Sohn W, Lee SP, Jun DW, Lee HL, Yoon BC, Choi HS, Hahm JS. J Korean Med Sci. 2013 Jun;28(6):901-7. doi: 10.3346/jkms.2013.28.6.901. Epub 2013 Jun 3.
  • Genetic and Physiological Responses of Bifidobacterium animalis subsp. lactis to Hydrogen Peroxide Stress. Oberg TS, Ward RE, Steele JL, Broadbent JR. J Bacteriol. 2013 Jun 14. [Epub ahead of print]
  • Breathing Nitric Oxide plus Hydrogen Gas Reduces Ischemia-Reperfusion Injury and Nitrotyrosine Production in Murine Heart. Shinbo T, Kokubo K, Sato Y, Hagiri S, Hataishi R, Hirose M, Kobayashi H. Am J Physiol Heart Circ Physiol. 2013 Jun 14. [Epub ahead of print]
  • Anion-exchange synthesis of nanoporous FeP nanosheets as electrocatalysts for hydrogen evolution reaction. Xu Y, Wu R, Zhang J, Shi Y, Zhang B. Chem Commun (Camb). 2013 Jun 17.


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+