enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 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. At standard temperature and pressure , two oxygen atoms will bind covalently to form dioxygen , a colorless and odorless diatomic gas with the chemical formula O

  3. Earth's outer core - Wikipedia

    en.wikipedia.org/wiki/Earth's_outer_core

    The light elements sulfur, silicon, oxygen, carbon, and hydrogen may constitute part of the outer core due to their abundance and ability to partition into liquid iron under certain conditions. The depletion of siderophile elements in Earth's mantle compared to chondritic meteorites is attributed to metal-silicate reactions during formation of ...

  4. Chalcogen - Wikipedia

    en.wikipedia.org/wiki/Chalcogen

    Oxygen also occurs in many minerals, being found in all oxide minerals and hydroxide minerals, and in numerous other mineral groups. [55] Stars of at least eight times the mass of the Sun also produce oxygen in their cores via nuclear fusion. [13] Oxygen is the third-most abundant element in the universe, making up 1% of the universe by weight ...

  5. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    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, carbon dioxide, iron oxides and silicates.

  6. Oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Oxygen_cycle

    The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as well as how it is used. The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [1]

  7. Solid oxygen - Wikipedia

    en.wikipedia.org/wiki/Solid_oxygen

    Solid oxygen forms at normal atmospheric pressure at a temperature below 54.36 K (−218.79 °C, −361.82 °F). Solid oxygen O 2 , like liquid oxygen , is a clear substance with a light sky-blue color caused by absorption in the red part of the visible light spectrum.

  8. AOL Mail - AOL Help

    help.aol.com/products/aol-webmail

    Get answers to your AOL Mail, login, Desktop Gold, AOL app, password and subscription questions. Find the support options to contact customer care by email, chat, or phone number.

  9. Atmosphere - Wikipedia

    en.wikipedia.org/wiki/Atmosphere

    The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. [2] Most organisms use oxygen for respiration ; lightning and bacteria perform nitrogen fixation which produces ammonia that is used to make nucleotides and amino acids ; plants , algae , and cyanobacteria use carbon ...