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Geological history of oxygen. Before photosynthesis evolved, Earth's atmosphere had no free diatomic oxygen (O 2 ). [ 2] Small quantities of oxygen were released by geological [ 3] and biological processes, but did not build up in the atmosphere due to reactions with reducing minerals. Oxygen began building up in the atmosphere at approximately ...
The origin of water on Earth is the subject of a body of research in the fields of planetary science, astronomy, and astrobiology. Earth is unique among the rocky planets in the Solar System in having oceans of liquid water on its surface. [ 2] Liquid water, which is necessary for all known forms of life, continues to exist on the surface of ...
MeSH. D021061. [ edit on Wikidata] Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen -rich liquid (such as a perfluorocarbon ), rather than breathing air, by selecting a liquid that can hold a large amount of oxygen and is capable of CO 2 gas exchange. [ 1]
The history of fluid mechanics is a fundamental strand of the history of physics and engineering. The study of the movement of fluids (liquids and gases) and the forces that act upon them dates back to pre-history. The field has undergone a continuous evolution, driven by human dependence on water, meteorological conditions and internal ...
Water is fundamental to both photosynthesis and respiration. Photosynthetic cells use the sun's energy to split off water's hydrogen from oxygen. [106] In the presence of sunlight, hydrogen is combined with CO 2 (absorbed from air or water) to form glucose and release oxygen. [107]
Isotope hydrology[ 1] is a field of geochemistry and hydrology that uses naturally occurring stable and radioactive isotopic techniques to evaluate the age and origins of surface and groundwater and the processes within the atmospheric hydrologic cycle. [ 2] Isotope hydrology applications are highly diverse, and used for informing water-use ...
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor is transparent, like most constituents of the atmosphere. [ 4] Under typical atmospheric conditions ...
Oxygen is used to perform several important functions in the steel manufacturing process. Many rockets and lunar landers use cryogenic gases as propellants. These include liquid oxygen, liquid hydrogen, and liquid methane. By freezing the automobile or truck tire in liquid nitrogen, the rubber is made brittle and can be crushed into small ...