Encyclopedia - Oxygen: Encyclopedia - Oxygen
Oxygen is a chemical element in the periodic table. It has the symbol O and atomic number 8. The element is very common, found not only o...   » Read the article

Encyclopedia - Oxygen: Encyclopedia Ii - Oxygen - Precautions
Oxygen can be toxic at elevated partial pressures (i.e. high relative concentrations). This is important in some forms of scuba diving, s...   » Read the article

Encyclopedia - Oxygen: Encyclopedia Ii - Oxygen - Applications
Liquid oxygen finds use as an oxidizer in rocket propulsion. Oxygen is essential to respiration, so oxygen supplementation has found use ...   » Read the article

Encyclopedia - Drowning: Encyclopedia - Drowning
Drowning is death caused by the filling of the lungs by a fluid, usually water, rendering breathing impossible and leading to death due t...   » Read the article

Encyclopedia - Alkane: Encyclopedia - Alkane
An alkane in organic chemistry is a saturated hydrocarbon without cycles, that is, an acyclic hydrocarbon in which the molecule has the m...   » Read the article

Encyclopedia - Anoxic Event: Encyclopedia - Anoxic Event
An anoxic event occurs when the Earth's oceans become completely depleted of O2 below the surface levels. Anoxic event - Occurrence. Ano...   » Read the article

Encyclopedia - Argon: Encyclopedia - Argon
Argon is a chemical element in the periodic table. It has the symbol Ar and atomic number 18. The third noble gas, in group 18, argon ma...   » Read the article

Encyclopedia - Chromium: Encyclopedia - Chromium
Chromium is a chemical element in the periodic table that has the symbol Cr and atomic number 24. Chromium - Notable characteristics. Ch...   » Read the article

Encyclopedia - Cryolite: Encyclopedia - Cryolite
Cryolite (Na3AlF6, sodium aluminium fluoride) is an uncommon mineral of very limited natural distribution. It is mostly identified with t...   » Read the article

Encyclopedia - Zircon: Encyclopedia - Zircon
Zircon is a mineral belonging to the group of nesosilicates. Its chemical formula is ZrSiO4. Hafnium is almost always present ranging fro...   » Read the article

Encyclopedia - Apollo 13: Encyclopedia - Apollo 13
Apollo 13 was an American space mission, part of the Apollo program. It was intended to be the third mission to land on the Moon, but ins...   » Read the article

Encyclopedia - Barium: Encyclopedia - Barium
Barium is a toxic chemical element in the periodic table that has the symbol Ba and atomic number 56. A soft silvery metallic element, b...   » Read the article

Encyclopedia - Anoxic Event: Encyclopedia Ii - Anoxic Event - Mechanism
The mechanism by which anoxic events occur is still very poorly understood. It is believed that, with the oceans very warm, and, in the c...   » Read the article

Encyclopedia - Anoxic Event: Encyclopedia Ii - Anoxic Event - Consequences
Anoxic events have had many important consequences. It is believed that they have been responsible for mass extinctions of marine organis...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Alkanes In Nature
Although alkanes occur in nature in various way, they do not rank biologically among the essential materials. Cycloalkanes with 14 to 18 ...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Occurrence
Alkanes occur both on Earth and in the solar system, however only the first hundred or so, and even then mostly only in traces. The light...   » Read the article

Encyclopedia - Drowning: Encyclopedia Ii - Drowning - The Drowning Process
Drowning - Common situations leading to drowning. Most drownings occur in water, drownings in other fluids are comparatively rare and o...   » Read the article

Encyclopedia - Anoxic Event: Encyclopedia Ii - Anoxic Event - Occurrence
Anoxic events occur only during periods of very warm climate characterised by high levels of CO2, usually above 1800 ppmv, and mean surfa...   » Read the article

Encyclopedia - Thiophene: Encyclopedia Ii - Thiophene - Synthesis And Occurrence
Thiophenes are prepared by the reaction of 1,4-diketones with sulfiding reagents such as Lawesson's reagent or P4S10. In fact, reflecting...   » Read the article

Encyclopedia - Drowning: Encyclopedia Ii - Drowning - Rescue And Treatment
Many pools and designated bathing areas either have either lifeguards, a pool safety camera system for local or remote monitoring, or com...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Reactions
Alkane - Reactions with oxygen. All alkanes react with oxygen in a combustion reaction, although they become increasing difficult to ig...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Nomenclature Of Alkanes
The names of all alkanes end with -ane. Alkane - Alkanes with unbranched carbon chains. The first four members of the series (in terms ...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Purification And Use
Alkanes are both important raw materials of the chemical industry and the most important fuels of the world economy. The starting materia...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Molecular Geometry
The molecular structure of the alkanes directly affects their physical and chemical characteristics. It is derived from the electron conf...   » Read the article

Encyclopedia - Alkane: Encyclopedia Ii - Alkane - Properties
Alkane - Physical properties. The molecular structure, particularly the surface area of the molecule, determines the boiling point of t...   » Read the article

Encyclopedia - Peroxisome: Encyclopedia Ii - Peroxisome - Occurrence And Evolution
Peroxisomes are found in all eukaryotic cells. Prokaryotes lack peroxisomes, so they are more vulnerable to toxic substances like hydroge...   » Read the article

Encyclopedia - Silicon: Encyclopedia Ii - Silicon - Occurrence
Silicon is a principal component of aerolites which are a class of meteoroids and also of tektites which is a natural form of glass. Meas...   » Read the article

Encyclopedia - Thiophene: Encyclopedia Ii - Thiophene - Properties
At room temperature, pure thiophene is a colorless liquid with mildly pleasant odor reminiscent of benzene, with which thiophene shares s...   » Read the article

Encyclopedia - Thiophene: Encyclopedia Ii - Thiophene - Uses
Thiophenes are important heterocyclic compounds and are recurring building blocks in organic chemistry with applications in pharmaceutica...   » Read the article

Encyclopedia - Phosphorus: Encyclopedia Ii - Phosphorus - Occurrence
Due to its reactivity to air and many other oxygen containing substances, phosphorus is not found free in nature but it is widely distrib...   » Read the article

Encyclopedia - Phosphorus: Encyclopedia Ii - Phosphorus - Occurrence
Due to its reactivity to air and many other oxygen containing substances, phosphorus is not found free in nature but it is widely distrib...   » Read the article

Encyclopedia - Hydrogen Sulfide: Encyclopedia Ii - Hydrogen Sulfide - Occurrence
Small amounts of hydrogen sulfide occur in crude petroleum but natural gas can contain up to 28%. Volcanoes and hot springs emit some H2S...   » Read the article

Encyclopedia - Organic Peroxide: Encyclopedia Ii - Organic Peroxide - Safety
Many organic chemicals form peroxides in presence of atmospheric oxygen and sometimes ultraviolet light; a typical example is the diethyl...   » Read the article

Encyclopedia - Organic Peroxide: Encyclopedia Ii - Organic Peroxide - Safety
Many organic chemicals form peroxides in presence of atmospheric oxygen and sometimes ultraviolet light; a typical example is the diethyl...   » Read the article

Encyclopedia - Chromium: Encyclopedia Ii - Chromium - Notable Characteristics
Chromium is a steel-gray, lustrous, hard metal that takes a high polish, melts with difficulty, and tarnishes. The most common oxidation ...   » Read the article

Encyclopedia - Argon: Encyclopedia Ii - Argon - Notable Characteristics
Argon is 2.5 times as soluble in water as nitrogen which is approximately the same solubility as oxygen. This highly stable chemical elem...   » Read the article

Encyclopedia - Peroxisome: Encyclopedia Ii - Peroxisome - Function
Peroxisomes contain oxidative enzymes, such as catalase, D-amino acid oxidase and uric acid oxidase. By using molecular oxygen, hydrogen ...   » Read the article

Encyclopedia - Aurora Astronomy: Encyclopedia Ii - Aurora Astronomy - Auroral Mechanism
Aurora is now known to be caused by electrons of typical energy of 1-15 keV, i.e. the energy obtained by the electrons passing through a ...   » Read the article

Encyclopedia - Phosphorus: Encyclopedia Ii - Phosphorus - Precautions
This is a particularly poisonous element with 50 mg being the average fatal dose (white phosphorus is generally considered to be the leth...   » Read the article

Encyclopedia - Chlorine: Encyclopedia Ii - Chlorine - History
Chlorine (Gr. χλωρος, greenish yellow) was discovered in 1774 by Carl Wilhelm Scheele, who mistakenly thought it contained oxygen. ...   » Read the article

Encyclopedia - Copper: Encyclopedia Ii - Copper - Biological Role
Copper is essential in all higher plants and animals. Copper is carried mostly in the bloodstream on a plasma protein called ceruloplasmi...   » Read the article

Encyclopedia - Carbon: Encyclopedia Ii - Carbon - History And Etymology
Carbon was discovered in prehistory and was known to the ancients, who manufactured it by burning organic material in insufficient oxygen...   » Read the article

Encyclopedia - Carbon: Encyclopedia Ii - Carbon - Organic Compounds
The most prominent oxide of carbon is carbon dioxide, CO2. This is a minor component of the Earth's atmosphere, produced and used by livi...   » Read the article

Encyclopedia - Beryllium: Encyclopedia Ii - Beryllium - Isotopes
Of beryllium's 10 isotopes, only beryllium-9 is stable. Cosmogenic beryllium-10 is produced in the atmosphere by cosmic ray spallation of...   » Read the article

Encyclopedia - Platinum: Encyclopedia Ii - Platinum - Notable Characteristics
The metal appears silvery-white when pure, and firm. The metal is corrosion-resistant. The catalytic properties of the six platinum famil...   » Read the article

Encyclopedia - Hydrogen Sulfide: Encyclopedia Ii - Hydrogen Sulfide - Chemistry
Hydrogen sulfide is a covalent hydride chemically related to water (H2O) since oxygen and sulfur occur in the same periodic table group. ...   » Read the article

Encyclopedia - Hydrogen Sulfide: Encyclopedia Ii - Hydrogen Sulfide - Health Effects
Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison several different systems in the body, although the ne...   » Read the article

Encyclopedia - Limnic Eruption: Encyclopedia Ii - Limnic Eruption - Consequences Of Limnic Eruptions
Once an eruption occurs, a large CO2 cloud forms above the lake and expands to the neighbouring region. Because CO2 is denser than air, i...   » Read the article

Encyclopedia - Manganese: Encyclopedia Ii - Manganese - Compounds
Potassium permanganate, also called Condy's crystals, is a commonly used laboratory reagent because of its oxidizing properties and finds...   » Read the article

Encyclopedia - Carbamate: Encyclopedia Ii - Carbamate - Carbamates In Biochemistry
The carbamate functional group is formed when a carbon dioxide molecule reacts with the amino terminus of a peptide chain or an amino gro...   » Read the article

Encyclopedia - Carbon: Encyclopedia Ii - Carbon - Organic Compounds
The most prominent oxide of carbon is carbon dioxide, CO2. This is a minor component of the Earth's atmosphere, produced and used by livi...   » Read the article

Encyclopedia - Tungsten: Encyclopedia Ii - Tungsten - Compounds
The most common oxidation state of tungsten is +6, but it exhibits all oxidation states from +2 to +6. Tungsten typically combines with o...   » Read the article

Encyclopedia - Tin: Encyclopedia Ii - Tin - Notable Characteristics
Tin is a malleable, ductile, highly crystalline, silvery-white metal whose crystal structure causes a strange screeching sound known as t...   » Read the article

Encyclopedia - Titanium: Encyclopedia Ii - Titanium - Notable Characteristics
Titanium is well known for its excellent corrosion resistance (almost as resistant as platinum), being able to withstand attack by acids,...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - Notable Characteristics
Tellurium is a relatively rare element, in the same chemical family as oxygen, sulfur, selenium, and polonium (the chalcogens). When crys...   » Read the article

Encyclopedia - Plutonium: Encyclopedia Ii - Plutonium - Compounds
Plutonium reacts readily with oxygen, forming PuO and PuO2, as well as intermediate oxides. It reacts with the halides, giving rise to co...   » Read the article

Encyclopedia - Phosphorus: Encyclopedia Ii - Phosphorus - Precautions
This is a particularly poisonous element with 50 mg being the average fatal dose (white phosphorus is generally considered to be the leth...   » Read the article

Encyclopedia - Manganese: Encyclopedia Ii - Manganese - Compounds
Potassium permanganate, also called Condy's crystals, is a commonly used laboratory reagent because of its oxidizing properties and finds...   » Read the article

Encyclopedia - Oxygen Depletion: Encyclopedia Ii - Oxygen Depletion - Causes Of Oxygen Depletion
Oxygen depletion could be the result of a number of factors including natural ones, but is of most concern as a consequence of pollution ...   » Read the article

Encyclopedia - Transposition Logic: Encyclopedia Ii - Transposition Logic - Form Of Transposition
In the inferred proposition, the consequent is the contradictory of the antecedent in the original proposition, and the antecedent of the...   » Read the article

Encyclopedia - Oxygen Depletion: Encyclopedia Ii - Oxygen Depletion - Causes Of Hypoxia
Oxygen depletion could be the result of a number of factors including natural ones, but is of most concern as a consequence of pollution ...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - Occurrence
Tellurium is sometimes found in its native form, but is more often found as the telluride of gold (calaverite), and combined with other m...   » Read the article

Encyclopedia - Hemangioma: Encyclopedia Ii - Hemangioma - Types
Hemangiomas are often classified by the size of the vessel affected. For example: Capillary hemangioma (or "capillary nevus hemangioma",...   » Read the article

Encyclopedia - Patent Ductus Arteriosus: Encyclopedia Ii - Patent Ductus Arteriosus - Overview
Patent ductus arteriosus - Normal ductus arteriosus closure. In the developing fetus, the ductus arteriosus (DA) is a shunt connecting ...   » Read the article

Encyclopedia - Kerogen: Encyclopedia Ii - Kerogen - Types
Labile kerogen breaks down to form heavy hydrocarbons (i.e. oils), refractory kerogen breaks down to form light hydrocarbons (i.e. gases)...   » Read the article

Encyclopedia - Caesium: Encyclopedia Ii - Caesium - Occurrence
An alkali metal, caesium occurs in lepidolite, pollucite (hydrated silicate of aluminium and caesium) and within other sources. One of th...   » Read the article

Encyclopedia - Beryllium: Encyclopedia Ii - Beryllium - Occurrence
Beryllium is an essential constituent of about 100 out of about 4000 known minerals, the most important of which are bertrandite (Be4Si2O...   » Read the article

Encyclopedia - Palladium: Encyclopedia Ii - Palladium - Occurrence
Palladium is found as a free metal and alloyed with platinum and gold with platinum group metals in placer deposits of the Ural Mountains...   » Read the article

Encyclopedia - Platinum: Encyclopedia Ii - Platinum - Occurrence
Platinum is often found as native platinum and alloyed with iridium as platiniridium. The platinum arsenide, sperrylite, is a major sourc...   » Read the article

Encyclopedia - Manganese Nodule: Encyclopedia Ii - Manganese Nodule - Occurrence
Nodules lie on the seabed sediment, often partly or completely buried. They vary greatly in abundance, in some cases touching one another...   » Read the article

Encyclopedia - Nitrogen Narcosis: Encyclopedia Ii - Nitrogen Narcosis - Mechanism
One of the important factors leading to its occurrence seems to be the vertical speed of the diver's descent. Pressure increases as the d...   » Read the article

Encyclopedia - Iron: Encyclopedia Ii - Iron - Occurrence
Iron is one of the more common elements on Earth, making up about 5% of the Earth's crust. Most of this iron is found in various iron oxi...   » Read the article

Encyclopedia - Chlorine: Encyclopedia Ii - Chlorine - Occurrence
In nature chlorine is found only as the chloride ion. Chlorides make up much of the salt dissolved in the Earth's oceans—about 1.9% of ...   » Read the article

Encyclopedia - Acid Mine Drainage: Encyclopedia Ii - Acid Mine Drainage - Occurrence
Subsurface mining often progresses below the water table, in which case water must be constantly pumped out of the mine in order to preve...   » Read the article

Encyclopedia - Organic Peroxide: Encyclopedia Ii - Organic Peroxide - Occurrence And Use
Organic peroxides find numerous uses in various industries, as accelerators, activators, catalysts, cross-linking agents, curing and vulc...   » Read the article

Encyclopedia - Iron: Encyclopedia Ii - Iron - Occurrence
Iron is one of the more common elements on Earth, making up about 5% of the Earth's crust. Most of this iron is found in various iron oxi...   » Read the article

Encyclopedia - Organic Peroxide: Encyclopedia Ii - Organic Peroxide - Occurrence And Use
Organic peroxides find numerous uses in various industries, as accelerators, activators, catalysts, cross-linking agents, curing and vulc...   » Read the article

Encyclopedia - Sulfur: Encyclopedia Ii - Sulfur - Occurrence
Elemental sulfur can be found near hot springs and volcanic regions in many parts of the world, especially along the Pacific Ring of Fire...   » Read the article

Encyclopedia - Hydrogen: Encyclopedia Ii - Hydrogen - Occurrence
Hydrogen is the most abundant element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms. [4] This e...   » Read the article

Encyclopedia - Hydrogen: Encyclopedia Ii - Hydrogen - Occurrence
Hydrogen is the most abundant element in the universe, making up 75% of normal matter by mass and over 90% by number of atoms. [4] This e...   » Read the article

Encyclopedia - Apollo 13: Encyclopedia Ii - Apollo 13 - Mission Highlights
When Apollo 13 was 321,860 kilometers (199,990 mi) from Earth, an oxygen tank in the service module exploded. The only solution was for t...   » Read the article

Encyclopedia - Zircon: Encyclopedia Ii - Zircon - Properties
Zircon is a remarkable mineral, if only for its almost ubiquitous presence in the crust of Earth. It is found in igneous rocks (as primar...   » Read the article

Encyclopedia - Firestorm: Encyclopedia Ii - Firestorm - Mechanism Of Firestorms In Furious Wildfires
In a larger fire, the firestorm is just where the leading edge of the fire is very intense. The large amount of flame at the fire front i...   » Read the article

Encyclopedia - Spontaneous Human Combustion: Encyclopedia Ii - Spontaneous Human Combustion - Some Survivors Of Alleged Shc
A number of persons have reported serious burns that injured their bodies with no apparent cause. If this is not the alleged phenomenon k...   » Read the article

Encyclopedia - Ionosphere: Encyclopedia Ii - Ionosphere - The Ionospheric Layers
Solar radiation, acting on the different compositions of the atmosphere with height, generates layers of ionization: Ionosphere - D Laye...   » Read the article

Encyclopedia - Carbon: Encyclopedia Ii - Carbon - Occurrence
There are nearly ten million carbon compounds known to science. Many thousands of these are vital to life processes. They are also many o...   » Read the article

Encyclopedia - Trace Fossil: Encyclopedia Ii - Trace Fossil - Examples
Trace fossils are found in abundance in rocks from the upper part of the Vendian period, some 550 million years ago, with the earliest oc...   » Read the article

Encyclopedia - Gold: Encyclopedia Ii - Gold - Occurrence
Due to its relative chemical inertness gold is usually found as the native metal or alloy. Occasionally large accumulations of native gol...   » Read the article

Encyclopedia - Gold: Encyclopedia Ii - Gold - Occurrence
Due to its relative chemical inertness gold is usually found as the native metal or alloy. Occasionally large accumulations of native gol...   » Read the article

Encyclopedia - Titanium: Encyclopedia Ii - Titanium - Occurrence And Production
Titanium metal is not found unbound to other elements in nature but the element is the ninth most abundant element in the Earth's crust (...   » Read the article

Encyclopedia - Gender: Encyclopedia Ii - Gender - Etymology And Usage
Gender comes from Middle English gendre, from Latin genus, all meaning "kind", "sort", or "type". Ultimately from the proto Indo European...   » Read the article

Encyclopedia - Gender: Encyclopedia Ii - Gender - Etymology And Usage
Gender comes from Middle English gendre, from Latin genus, all meaning "kind", "sort", or "type". Ultimately from the proto Indo European...   » Read the article

Encyclopedia - Herbig-haro Object: Encyclopedia Ii - Herbig-haro Object - Discovery And History Of Observations
The first Herbig-Haro object was observed in the late 19th century by Burnham, when he looked at the star T Tauri with the 36-inch refrac...   » Read the article

Encyclopedia - Goldfish: Encyclopedia Ii - Goldfish - History
During the Tang Dynasty, it was popular for Chinese ponds to have carps. As the result of a genetic mutation one of these carp displayed ...   » Read the article

Encyclopedia - Igneous Rock: Encyclopedia Ii - Igneous Rock - Mineralogical Classification
For volcanic rocks, mineralogy is important in classifying and naming lavas. The most important criteria is the phenocryst species, follo...   » Read the article

Encyclopedia - Myocardial Infarction: Encyclopedia Ii - Myocardial Infarction - Treatment
A heart attack, especially because of cardiac arrhythmias, is often a life-threatening medical emergency which demands both immediate att...   » Read the article

Encyclopedia - Myocardial Infarction: Encyclopedia Ii - Myocardial Infarction - Treatment
A heart attack, especially because of cardiac arrhythmias, is often a life-threatening medical emergency which demands both immediate att...   » Read the article

Encyclopedia - Oxygen: Encyclopedia Ii - Oxygen - Characteristics
At standard temperature and pressure, oxygen exists as a diatomic molecule with the formula O2, in which the two oxygen atoms are doubly ...   » Read the article

Encyclopedia - Oxygen: Encyclopedia Ii - Oxygen - History
Oxygen was first discovered by Michał Sędziwój, Polish alchemist and philosopher in late 16th century. Sędziwój assumed the existenc...   » Read the article

Article - Popular Pages Sitemap Viii - O
This is a sitemap for Popular Pages VIII - O . Click on a link and you will find multiple definitions and articles related to the word....   » Read the article