In elemental state, oxygen is a gas in the atmosphere and is dissolved in water. The amount of relatively reactive oxygen elemental remains constant only in long run, because O2 producing plants replace much as of aerobic breathing creatures as well as other combustion processes is used again (oxygen for energy). Without this biological cycle O2 would only occur in compounds, ie elemental O2 exists in a dynamic equilibrium.
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
Oxygen is not created in primordial nucleosynthesis, but is produced in relatively large amounts in giant stars by helium burning. It is first formed from three helium nuclei 12C (Triple-alpha process), which subsequently merged with another helium nucleus to 16O. 18O is formed by fusion of 4He with a 14N nucleus.
Even in so-called main sequence stars like the sun plays a role in energy oxygen. In CNO cycle (CNO cycle) represents O2 is an intermediate of nuclear reaction in which proton capture by a 12C nucleus, which acts as a catalyst, a 4He nucleus (alpha particle) is produced. In extremely heavy stars occurs in late stage of their development to O2 burning, in which the O2 is used as nuclear fuel for reactions that lead to construction of even heavier nuclei.
With the discovery of O2 its meaning was not clear during combustion. The Frenchman Antoine Lavoisier found in his experiments that during combustion does not escape phlogiston, but O2 is bound. By weighing it demonstrated that a substance after combustion was not easier but harder. This was caused by the additional weight of ingested during the combustion process oxygen.
Since these orbitals are completely filled with electrons, they do not contribute to binding. From the 2p orbitals are a total of six molecular orbitals with different energy level. The orbitals have this same energy. Electrons are distributed in molecular orbitals, it comes to following breakdown of eight p-electrons. These two valence electrons determine the properties of O2 molecule. O2 has allowed a total of three and energetically accessible quantum states for the distribution of these electrons.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The most common stable oxygen isotope 16O (99.76%), in addition still comes 18O (0.20%) and 17O (0.037%) before. In addition to the stable oxygen isotopes are still a total of 13 unstable, radioactive nuclides from 12O to 28O are known which are artificially produced. Their half lives often are only milliseconds to seconds, with two minutes 15O this case has the longest half-life, and is frequently used in positron emission tomography.
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
Oxygen is not created in primordial nucleosynthesis, but is produced in relatively large amounts in giant stars by helium burning. It is first formed from three helium nuclei 12C (Triple-alpha process), which subsequently merged with another helium nucleus to 16O. 18O is formed by fusion of 4He with a 14N nucleus.
Even in so-called main sequence stars like the sun plays a role in energy oxygen. In CNO cycle (CNO cycle) represents O2 is an intermediate of nuclear reaction in which proton capture by a 12C nucleus, which acts as a catalyst, a 4He nucleus (alpha particle) is produced. In extremely heavy stars occurs in late stage of their development to O2 burning, in which the O2 is used as nuclear fuel for reactions that lead to construction of even heavier nuclei.
With the discovery of O2 its meaning was not clear during combustion. The Frenchman Antoine Lavoisier found in his experiments that during combustion does not escape phlogiston, but O2 is bound. By weighing it demonstrated that a substance after combustion was not easier but harder. This was caused by the additional weight of ingested during the combustion process oxygen.
Since these orbitals are completely filled with electrons, they do not contribute to binding. From the 2p orbitals are a total of six molecular orbitals with different energy level. The orbitals have this same energy. Electrons are distributed in molecular orbitals, it comes to following breakdown of eight p-electrons. These two valence electrons determine the properties of O2 molecule. O2 has allowed a total of three and energetically accessible quantum states for the distribution of these electrons.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The most common stable oxygen isotope 16O (99.76%), in addition still comes 18O (0.20%) and 17O (0.037%) before. In addition to the stable oxygen isotopes are still a total of 13 unstable, radioactive nuclides from 12O to 28O are known which are artificially produced. Their half lives often are only milliseconds to seconds, with two minutes 15O this case has the longest half-life, and is frequently used in positron emission tomography.
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