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  2. 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 ...

  3. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    Given the ubiquity of hydrogen atoms in inorganic and organic chemical compounds, the hydrogen cycle is focused on molecular hydrogen (H 2). Nitrogen The nitrogen cycle is the process by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere , terrestrial , and marine ecosystems .

  4. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...

  5. Chemical cycling - Wikipedia

    en.wikipedia.org/wiki/Chemical_cycling

    In most hydrogen-fusing stars, including the Sun, a chemical cycle involved in stellar nucleosynthesis occurs which is known as a carbon-nitrogen-oxygen or . In addition to this cycle, stars also have a helium cycle. [1] Various cycles involving gas and dust have been found to occur in galaxies. [2]

  6. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]

  7. Texas could bus migrants directly to ICE for deportation ...

    www.aol.com/texas-planning-bus-migrants-directly...

    Texas is looking at a plan to ramp up migrant buses again — but instead of sending them to sanctuary cities, officials would ship newly arrived illegal migrants directly to ICE holding centers ...

  8. US appeals court halts enforcement of anti-money laundering law

    www.aol.com/news/us-appeals-court-halts...

    By Nate Raymond (Reuters) -A U.S. appeals court has halted enforcement of an anti-money laundering law that requires corporate entities to disclose the identities of their real beneficial owners ...

  9. 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 ...