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  2. Hydrogen - Wikipedia

    en.wikipedia.org/wiki/Hydrogen

    Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H 2, sometimes called dihydrogen, [11] hydrogen gas, molecular hydrogen, or simply hydrogen. It is colorless, odorless, [12] non-toxic, and highly combustible.

  3. Biohydrogen - Wikipedia

    en.wikipedia.org/wiki/Biohydrogen

    Biological hydrogen production is also observed in nitrogen-fixing cyanobacteria. This microorganisms can grow forming filaments. This microorganisms can grow forming filaments. Under nitrogen-limited conditions some cells can specialize and form heterocysts , which ensures an anaerobic intracellular space to ease N 2 fixation by the ...

  4. Hydrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_cycle

    The hydrogen cycle consists of hydrogen exchanges between biotic (living) and abiotic (non-living) sources and sinks of hydrogen-containing compounds. Hydrogen (H) is the most abundant element in the universe. [1] On Earth, common H-containing inorganic molecules include water (H 2 O), hydrogen gas (H 2), hydrogen sulfide (H 2 S), and ammonia ...

  5. Glossary of biology - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_biology

    This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms.It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of cell biology, Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology ...

  6. Chemosynthesis - Wikipedia

    en.wikipedia.org/wiki/Chemosynthesis

    Venenivibrio stagnispumantis gains energy by oxidizing hydrogen gas.. In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrogen sulfide) or ferrous ions as a source of energy, rather than sunlight, as in ...

  7. Hydrogen atom - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_atom

    Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen.The electrically neutral hydrogen atom contains a single positively charged proton in the nucleus, and a single negatively charged electron bound to the nucleus by the Coulomb force.

  8. 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.

  9. H2 - Wikipedia

    en.wikipedia.org/wiki/H2

    Armenia 2 (H2), a private television company broadcasting in Armenia and Nagorno-Karabakh; H2 (A&E Networks), the rebranded name of the former channel History International. H2 (American TV channel), the American version of the channel; H2, a baseball manga by Mitsuru Adachi; Halo 2, a video game for the Xbox, created and developed by Bungie