H
1.008Hydrogen
Hidrojen
Hydrogen is the lightest and most abundant chemical element in the universe. It forms water, fuels stars, and is central to acids, fuels and many industrial reactions.
1
1.008 g/mol
1s¹
1
2.2
9.00e-5 g/cm³
-259.1 °C
-252.9 °C
Henry Cavendish
Henry Cavendish isolated hydrogen gas in 1766 and described it as inflammable air. Antoine Lavoisier later named it hydrogen, from Greek roots meaning water-former, after showing that water is made from hydrogen and oxygen.
Protium
Natural abundance: 99.9885%. The most common hydrogen isotope; its nucleus contains one proton and no neutrons.Deuterium (D)
Natural abundance: 0.0115%. A stable isotope with one neutron; used in heavy water (D₂O).Tritium (T)
Natural abundance: Trace amounts. Half-life: 12.32 years. Radioactive; used in fusion research and tracing applications.H₂O
WaterUniversal solvent and the foundation of life on Earth.H₂O₂
Hydrogen PeroxideOxidizer used in bleaching, disinfection and chemical synthesis.HCl
Hydrochloric AcidStrong acid used in industry and present in gastric acid.NH₃
AmmoniaKey feedstock for nitrogen fertilizers.CH₄
MethaneMain component of natural gas.- Fuel cells and clean-energy systems
- Ammonia production by the Haber-Bosch process
- Hydrogenation of oils and industrial chemicals
- Liquid hydrogen rocket fuel
- Hydrodesulfurization in petroleum refining
Hydrogen is essential in water and organic molecules. Hydrogen ions are also central to pH, acid-base balance and proton gradients used in cellular energy production.
- Hydrogen accounts for roughly three quarters of the mass of visible matter in the universe.
- In the Sun, hydrogen nuclei fuse into helium and release the energy that powers sunlight.
- Hydrogen has the lowest density of all chemical elements.
- Hydrogen fuel cells produce water as the main exhaust product.
- Hydrogen has atomic number 1, so a neutral hydrogen atom has one proton and one electron.
- The electron configuration of hydrogen is 1s¹.
- In water electrolysis, hydrogen gas forms at the cathode while oxygen forms at the anode.
- Hydrogen can have an oxidation state of +1 in many compounds and -1 in metal hydrides.
What is the atomic number of hydrogen?
The atomic number of hydrogen is 1.
What is the electron configuration of hydrogen?
Hydrogen has the electron configuration 1s¹.
What are the main isotopes of hydrogen?
The main isotopes are protium, deuterium and tritium.
Where does hydrogen form during water electrolysis?
In water electrolysis, hydrogen gas forms at the cathode while oxygen forms at the anode.
What is hydrogen used for?
Hydrogen is used in fuel cells, ammonia production, hydrogenation, rocket fuel and petroleum refining.