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  2. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    Stage 3 (1.85–0.85 Ga): O 2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer. Stages 4 and 5 (0.85 Ga–present): O 2 sinks filled, the gas accumulates. [1] Although oxygen is the most abundant element in Earth's crust, due to its high reactivity it mostly exists in compound forms such as water ...

  3. Isopropyl alcohol - Wikipedia

    en.wikipedia.org/wiki/Isopropyl_alcohol

    Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable, organic compound with a pungent alcoholic odor. [9]Isopropyl alcohol, an organic polar molecule, is miscible in water, ethanol, and chloroform, demonstrating its ability to dissolve a wide range of substances including ethyl cellulose, polyvinyl butyral, oils, alkaloids, and natural ...

  4. Hydroxy group - Wikipedia

    en.wikipedia.org/wiki/Hydroxy_group

    In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion HO−, called hydroxide, and the neutral radical HO ...

  5. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    Stages 4 and 5 (0.85 Ga – present): Other O 2 reservoirs filled; gas accumulates in atmosphere. [1] The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [2] was a time interval during the Earth 's Paleoproterozoic era when the Earth's atmosphere ...

  6. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Oxygen is the most abundant element in Earth's crust, and the third-most abundant element in the universe after hydrogen and helium. 2. Dioxygen gas currently constitutes 20.95% molar fraction of the Earth's atmosphere, though this has changed considerably over long periods of time in Earth's history.

  7. Cellular respiration - Wikipedia

    en.wikipedia.org/wiki/Cellular_respiration

    Cellular respiration is the process by which biological fuels are oxidised in the presence of an inorganic electron acceptor, such as oxygen, to produce large amounts of energy and drive the bulk production of ATP. Anaerobic respiration is used by microorganisms, either bacteria or archaea, in which neither oxygen (aerobic respiration) nor ...

  8. Oxygen storage - Wikipedia

    en.wikipedia.org/wiki/Oxygen_storage

    Most humans can function at rest with an oxygen level of 15% at one atmosphere pressure; [1] a fuel such as methane is combustable down to 12% oxygen in nitrogen. A small room of 10 meter 3 has 2.08 meter 3 (2080 liters) or 2.99 kg of oxygen which would occupy 2.62 liters if it was liquid. [2]

  9. NOx - Wikipedia

    en.wikipedia.org/wiki/NOx

    In atmospheric chemistry, NOx is shorthand for nitric oxide (NO) and nitrogen dioxide (NO2), the nitrogen oxides that are most relevant for air pollution. [1][2] These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone. NOx gases are usually produced from the reaction between nitrogen and oxygen ...