When.com Web Search

  1. Ad

    related to: tầm quan trọng của oxygen

Search results

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

    en.wikipedia.org/wiki/Oxygen

    Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun's mass is oxygen. [19] Oxygen constitutes 49.2% of the Earth's crust by mass [69] as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust.

  3. Oxygen transmission rate - Wikipedia

    en.wikipedia.org/wiki/Oxygen_transmission_rate

    Oxygen transmission rate (OTR) is the measurement of the amount of oxygen gas that passes through a substance over a given period. It is mostly carried out on non-porous materials, where the mode of transport is diffusion, but there are a growing number of applications where the transmission rate also depends on flow through apertures of some description.

  4. Effect of oxygen on chronic obstructive pulmonary disease

    en.wikipedia.org/wiki/Effect_of_oxygen_on...

    Many people with chronic obstructive pulmonary disease have a low partial pressure of oxygen in the blood and high partial pressure of carbon dioxide.Treatment with supplemental oxygen may improve their well-being; alternatively, in some this can lead to the adverse effect of elevating the carbon dioxide content in the blood (hypercapnia) to levels that may become toxic.

  5. Oxygen saturation - Wikipedia

    en.wikipedia.org/wiki/Oxygen_saturation

    Dissolved oxygen levels required by various species in the Chesapeake Bay (US). In aquatic environments, oxygen saturation is a ratio of the concentration of "dissolved oxygen" (DO, O 2), to the maximum amount of oxygen that will dissolve in that water body, at the temperature and pressure which constitute stable equilibrium conditions.

  6. Allotropes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Allotropes_of_oxygen

    There are several known allotropes of oxygen. The most familiar is molecular oxygen (O 2), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (O 3). Others are: Atomic oxygen (O 1), a free radical. Singlet oxygen (O * 2), one of two metastable states of ...

  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. Isotopes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_oxygen

    Temperatures on the order of 10 9 kelvins are needed to fuse oxygen into sulfur. [11] An atomic mass of 16 was assigned to oxygen prior to the definition of the unified atomic mass unit based on 12 C. [12] Since physicists referred to 16 O only, while chemists meant the natural mix of isotopes, this led to slightly different mass scales.

  9. VO2 max - Wikipedia

    en.wikipedia.org/wiki/VO2_max

    V̇O 2 max (also maximal oxygen consumption, maximal oxygen uptake or maximal aerobic capacity) is the maximum rate of oxygen consumption attainable during physical exertion. [1] [2] The name is derived from three abbreviations: "V̇" for volume (the dot over the V indicates "per unit of time" in Newton's notation), "O 2" for oxygen, and "max" for maximum and usually normalized per kilogram of ...

  1. Ad

    related to: tầm quan trọng của oxygen