When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Hydrogen - Wikipedia

    en.wikipedia.org/wiki/Hydrogen

    Hydrogen was liquefied by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. Liquid hydrogen is a common rocket propellant, and it can also be used as the fuel for an internal combustion engine or fuel cell. [citation needed]

  3. Hydrogen production - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_production

    Hydrogen gas is produced by several industrial methods. [1] Nearly all of the world's current supply of hydrogen is created from fossil fuels. [2] [3]: 1 Most hydrogen is gray hydrogen made through steam methane reforming. In this process, hydrogen is produced from a chemical reaction between steam and methane, the main component of natural gas.

  4. Hydrogen atom - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_atom

    A hydrogen atom is an atom of the chemical element hydrogen. ... Free protons are common in the interstellar medium, and solar wind.

  5. Hydrogen compounds - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_compounds

    Hydrogen compounds are compounds containing the element hydrogen. In these compounds, hydrogen can form in the +1 and -1 oxidation states. Hydrogen can form compounds both ionically and in covalent substances. It is a part of many organic compounds such as hydrocarbons as well as water and other organic substances.

  6. Abundance of elements in Earth's crust - Wikipedia

    en.wikipedia.org/wiki/Abundance_of_elements_in...

    Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.

  7. Abundance of the chemical elements - Wikipedia

    en.wikipedia.org/wiki/Abundance_of_the_chemical...

    The abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.

  8. Isotopes of hydrogen - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_hydrogen

    Hydrogen is the only element whose isotopes have different names that remain in common use today: 2 H is deuterium [6] and 3 H is tritium. [7] The symbols D and T are sometimes used for deuterium and tritium; IUPAC ( International Union of Pure and Applied Chemistry ) accepts said symbols, but recommends the standard isotopic symbols 2 H and 3 ...

  9. Hydrogen ion - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_ion

    The concentration of hydrogen ions and pH are inversely proportional; in an aqueous solution, an increased concentration of hydrogen ions yields a low pH, and subsequently, an acidic product. By definition, an acid is an ion or molecule that can donate a proton, and when introduced to a solution it will react with water molecules (H 2 O) to ...