The Element Oxygen
Oxygen ('Octium') is a chemical element in the periodic table that has the symbol O and atomic number 8. The element is very common, found not only on Earth but throughout the universe. Molecular oxygen (O2) (often called free oxygen) on Earth is thermodynamically unstable. Its initial appearance was due to the action of photosynthetic anaerobes and its ubiquity in later epochs has been largely facilitated by terrestrial plants, which release oxygen during photosynthesis.
O Atomoxetine
What can be the oxidation state of each oxygen atom in oxygen difluoride? Follow asked 4 mins ago. Kanchan tolani Kanchan tolani. New contributor. Kanchan tolani is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Oxygen Atom Oxygen atoms are reduced into oxide ions on the porous cathode surface by electrons, and then flow through the ceramic electrolyte to the fuel rich porous anode where the oxide ions react with fuel (hydrogen), giving up electrons. From: Fuel Cells, 2013.
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| General | |||||||||||||||||||||||||
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| Name, Symbol, Number | Oxygen, O, 8 | ||||||||||||||||||||||||
| Chemical series | nonmetals | ||||||||||||||||||||||||
| Group, Period, Block | 16 (VIA), 2 , p | ||||||||||||||||||||||||
| Density, Hardness | 1.429 kg/m3(273K), NA | ||||||||||||||||||||||||
| Appearance | colorless | ||||||||||||||||||||||||
| Atomic properties | |||||||||||||||||||||||||
| Atomic weight | 15.9994 amu | ||||||||||||||||||||||||
| Atomic radius (calc.) | 60 (48) pm | ||||||||||||||||||||||||
| Covalent radius | 73 pm | ||||||||||||||||||||||||
| van der Waals radius | 152 pm | ||||||||||||||||||||||||
| Electron configuration | [He]2s22p4 | ||||||||||||||||||||||||
| e- 's per energy level | 2, 6 | ||||||||||||||||||||||||
| Oxidation states (Oxide) | -2,-1 (neutral) | ||||||||||||||||||||||||
| Crystal structure | cubic | ||||||||||||||||||||||||
| Physical properties | |||||||||||||||||||||||||
| State of matter | gas (paramagnetic) | ||||||||||||||||||||||||
| Melting point | 50.35 K (-368.77 °F) | ||||||||||||||||||||||||
| Boiling point | 90.18 K (-297.08 °F) | ||||||||||||||||||||||||
| Molar volume | 17.36 ×10-6 m3/mol | ||||||||||||||||||||||||
| Heat of vaporization | 3.4099 kJ/mol | ||||||||||||||||||||||||
| Heat of fusion | 0.22259 kJ/mol | ||||||||||||||||||||||||
| Vapor pressure | __ Pa at __ K | ||||||||||||||||||||||||
| Speed of sound | 317.5 m/s at 293 K | ||||||||||||||||||||||||
| Miscellaneous | |||||||||||||||||||||||||
| Electronegativity | 3.44 (Pauling scale) | ||||||||||||||||||||||||
| Specific heat capacity | 920 J/(kg*K) | ||||||||||||||||||||||||
| Electrical conductivity | ND 106/m ohm | ||||||||||||||||||||||||
| Thermal conductivity | 0.02674 W/(m*K) | ||||||||||||||||||||||||
| 1st ionization potential | 1313.9 kJ/mol | ||||||||||||||||||||||||
| 2nd ionization potential | 3388.3 kJ/mol | ||||||||||||||||||||||||
| 3rd ionization potential | 5300.5 kJ/mol | ||||||||||||||||||||||||
| 4th ionization potential | 7469.2 kJ/mol | ||||||||||||||||||||||||
| Most stable isotopes | |||||||||||||||||||||||||
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| SI units & STP are used except where noted. | |||||||||||||||||||||||||
Notable characteristics
- By Making Two Covalent Bonds, An O Atom With 8 Protons Fills Its Valence Shell.
- Atom: noun the smallest particle of an element that can exist either alone or in combination. The atom considered as a source of vast potential constructive or destructive energy.
- O 3 is ozone, such as occurs in Earth's upper atmosphere, and O (one atom), is atomic oxygen. Atomic oxygen doesn't exist naturally for very long on the surface of Earth, as it is very reactive. But in space, where there is plenty of ultraviolet radiation, O 2 molecules are more easily broken apart to create atomic oxygen.
At standard temperature and pressure, oxygen is found as a gas consisting of two oxygen atoms, chemical formula O2. This oxygen is an important component of air, produced by plants during photosynthesis and is necessary for animals' respiration. The word oxygen derives from two words in Greek, the Greek oxus (acid) and geinomai (engender). (A misnomer, as there are many acids which do not contain oxygen.)
Liquid oxygen and solid oxygen have a light blue color and both are highly paramagnetic. Liquid oxygen is usually obtained by the fractional distillation of liquid air.
Applications
Oxygen finds considerable use as an oxidizer, with only fluorine having a higher electronegativity. Liquid oxygen finds use as an oxidizer in rocket propulsion. Oxygen is essential to respiration, so oxygen supplementation has found use in medicine. People who climb mountains or fly in airplanes sometimes have supplemental oxygen supplies (as air). Oxygen is used in welding, and in the making of steel and methanol.
O Atomic Number
Oxygen, as a mild euphoric, has a history of recreational use that extends into modern times. Oxygen bars can be seen at parties to this day. Instagram firefox plugin. In the 19th century, oxygen was often mixed with nitrous oxide to promote a kind of analgesic effect. Fet amplifier frequency response.
History
O Atomic Mass
Oxygen was discovered by the Swedish pharmacist Karl Wilhelm Scheele in 1771, but this discovery was not immediately recognized, and the independent discovery by Joseph Priestley on August 1st 1774 was more widely known. It was named by Antoine Laurent Lavoisier in 1774.
Occurrence
O Atom
Oxygen is the most abundant element in the Earth's crust, estimated to comprise 46.7% of it. Oxygen comprises about 87% of the oceans (as H2O, water) and 20% of the atmosphere of Earth (as O2, molecular oxygen, or O3, ozone). Oxygen compounds, particularly metal oxides, silicates (SiO44-) and carbonates (CO32-), are commonly found in rocks and soil. Frozen water is a common solid on the outer planets and comets. The ice caps of Mars are made of frozen carbon dioxide. Oxygen compounds are found throughout the universeand the spectrum of oxygen is often seen in stars.
Compounds
Due to its electronegativity, oxygen forms chemical bonds with almost all other elements (which is the origin of the original definition of oxidation). The only elements to escape the possibility of oxidation are a few of the noble gases. The most famous of these oxides is of course hydrogen oxide, or water (H2O). Other well known examples include compounds of carbon and oxygen, such as carbon dioxide (CO2), alcohols (R-OH), aldehydes, (R-CHO), and carboxylic acids (R-COOH). Oxygenated radicals such as chlorates (ClO3-), perchlorates (ClO4-), chromates (CrO42-), dichromates (Cr2O72-), permanganates (MnO4-), and nitrates (NO3-)are strong oxidizing agents in and of themselves. Many metals such as Iron bond with oxygen atoms, iron (III) oxide (Fe2O3). Ozone (O3) is formed by electrostatic discharge in the presence of molecular oxygen. A double oxygen molecule (O2)2 is known, found as a minor component of liquid oxygen. Epoxides are ethers in which the oxygen atom is part of a ring of three atoms.
Isotopes
Oxygen has three stable isotopes and ten known radioactive isotopes. The radioisotopes all have half lives of less than three minutes.
Precautions
Oxygen can be toxic at elevated partial pressures.
Certain derivatives of oxygen, such as ozone (O3), hydrogen peroxide, hydroxyl radicals and superoxide, are also highly toxic. The body has developed mechanisms to protect against these toxic species. For instance, the naturally-occurring glutathione can act as an antioxidant, as can bilirubin which is normally a breakdown product of hemoglobin. Highly concentrated sources of oxygen promote rapid combustion and therefore are fire and explosion hazards in the presence of fuels. This is true as well of compounds of oxygen such as chlorates, perchlorates, dichromates, etc. Compounds with a high oxidative potential can often cause chemical burns.
The fire that killed the Apollo 1 crew on a test launchpad spread so rapidly because the pure oxygen atmosphere was at normal atmospheric pressure instead of the one third pressure that would be used during an actual launch. (see partial pressure)
See also
- Winkler test for dissolved oxygen for instructions on how to determine the amount of oxygen dissolved in fresh water.
- Combustion.
- Oxidation.
- The role of Oxygen as a diving breathing gas.
O Atomic Radii
Reference
- Los Alamos National Laboratory – Oxygen(http://periodic.lanl.gov/elements/8.html)
External links
- Los Alamos National Laboratory – Oxygen(http://periodic.lanl.gov/elements/8.html)
- WebElements.com – Oxygen(http://www.webelements.com/webelements/elements/text/O/index.html)
- EnvironmentalChemistry.com – Oxygen(http://environmentalchemistry.com/yogi/periodic/O.html)
- It's Elemental – Oxygen(http://education.jlab.org/itselemental/ele008.html)
- Oxygen Therapy – The First 150 Years(http://www.mtsinai.org/pulmonary/papers/ox-hist/ox-hist-intro.html)
- Oxygen Toxicity(http://members.tripod.com/tjaartdb0/html/oxygen_toxicity.html)