actinium

Acetic acid, also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. Pure water-free acetic acid is a colourless hygroscopic liquid (that is, it readily absorbs water) that freezes below 16.7 °C (62 °F) to a colourless crystalline solid. Acetic acid is corrosive, and its vapour is irritating to eyes and nose, although it is a weak acid based ...

Including:

• Acetic acid - Nomenclature
• Acetic acid - History
• Acetic acid - Chemical properties
• Acetic acid - Biochemistry
• Acetic acid - Production
• Acetic acid - Methanol carbonylation
• Acetic acid - Acetaldehyde oxidation
• Acetic acid - Ethylene oxidation
• Acetic acid - Fermentation
• Acetic acid - Applications
• Acetic acid - Vinyl acetate monomer
• Acetic acid - Acetic anhydride
• Acetic acid - Ester production
• Acetic acid - Vinegar
• Acetic acid - Use as solvent
• Acetic acid - Other applications
• Acetic acid - Safety

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Acetate, or ethanoate, is the anion of a salt or ester of acetic acid. The acetate ion has the formula CH3COO-, and is the conjugate base of acetic acid. Acetate can also refer to cellulose acetate, especially fibers or other derived products such as the acetate disc used in audio record production. Acetate can be found in many household products. Historically (prior to the discovery and naming of actinium) the abbreviation Ac (or AC) was sometimes used in c ...

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The abundance of a chemical element measures how common the element is, or how much of the element there is. Abundance of the chemical elements - Abundance of elements in the Universe. Hydrogen is the most abundant element in the known Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8. All others are orders of magnitude less common. Both helium-3 and helium-4 were produced in th ...

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• Abundance of the chemical elements - Abundance of elements in the Universe
• Abundance of the chemical elements - Abundance of elements in the Solar System
• Abundance of the chemical elements - Abundance of elements in Earth
• Abundance of the chemical elements - Abundance of elements in Earth's crust
• Abundance of the chemical elements - Ocean
• Abundance of the chemical elements - Atmosphere
• Abundance of the chemical elements - Organisms
• Abundance of the chemical elements - Human body

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Acetyl (IUPAC name ethanoyl) is the acyl of acetic acid, with chemical formula -COCH3, sometimes abbreviated to Ac (not to be confused with the element actinium). A molecule containing an acetyl group has the chemical structure . (where R denotes the remainder of the molecule.) The acetyl radical contains a methyl group single-bonded to a carbonyl. The carbon of the carbonyl has an lone electron available, with which it forms a ch ...

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The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. The actinide series is named after actinium. All actinides are f-block elements except lawrencium. There are also alternative arrangements which do not include either actinium or lawrencium in the actinide series. The actinides display less similarity in their chemical properties than the lanthanide series, for instance exhibiting a wider range of oxidation states, which initially led to confusion as to whether actinium, thorium and uranium should be consider d ...

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Beryllium is the chemical element in the periodic table that has the symbol Be and atomic number 4. A toxic bivalent element, beryllium is a steel grey, strong, light-weight yet brittle, alkaline earth metal, that is primarily used as a hardening agent in alloys (most notably, beryllium copper). Beryllium - Notable characteristics. Beryllium has one of the highest melting points of the light metals. The modulus of elasticity of beryllium is approximately 1/3 greater than that of steel. It has excelle ...

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• Beryllium - Notable characteristics
• Beryllium - Applications
• Beryllium - History
• Beryllium - Occurrence
• Beryllium - Isotopes
• Beryllium - Precautions
• Beryllium - Health effects

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Eighty-nine is the 24th prime number, following 83 and preceding 97. 89 is a Chen prime. It is the smallest Sophie Germain prime to start a Cunningham chain of the first kind of six terms, {89, 179, 359, 719, 1439, 2879}. 89 is an Eisenstein prime with no imaginary part and real part of the form 3n − 1. 89 is a Fibonacci number. Its reciprocal has a curious relationship to the Fibonacci sequence F(n): 89 is also a Markov number, appearing in solutions to the Markov Diophantine equati ...

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89 number, 89 number - In mathematics, 89 number - In astronomy, 89 number - In other fields

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Radon is a carcinogenic gas. Radon is a radioactive material and must be handled with care at all times. It is hazardous to inhale this element since it emits alpha particles. Also, its solid decay products, and their respective products, tend to form a fine dust which can easily enter the airways and become permanently stuck in lung tissue, producing heavy localized exposure. Rooms where radium, actinium, or thorium are stored should be well-ventilated in order to prevent build-up in the air. The build-up of radon is a potential heal ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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There's antimony, arsenic, aluminum, selenium, And hydrogen and oxygen and nitrogen and rhenium, And nickel, neodymium, neptunium, germanium, And iron, americium, ruthenium, uranium, Europium, zirconium, lutetium, vanadium, And lanthanum and osmium and astatine and radium, And gold and protactinium and indium and gallium, And iodine and thorium and thulium and thallium. There's yttrium, ytterbium, actinium, rubidium, And boron, gadolinium, niobium, iridium, And strontium and silicon and silver and samarium, And bismuth, bromine, l ...

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The Elements song, The Elements song - Lyrics, The Elements song - Periodic Table according to Lehrer

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Beryllium is an essential constituent of about 100 out of about 4000 known minerals, the most important of which are bertrandite (Be4Si2O7(OH)2), beryl (Al2Be3Si6O18), chrysoberyl (Al2BeO4), and phenakite (Be2SiO4). Precious forms of beryl are aquamarine and emerald. Along with hydrogen, helium, and lithium, som ...

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Beryllium, Beryllium - Notable characteristics, Beryllium - Applications, Beryllium - History, Beryllium - Occurrence, Beryllium - Isotopes, Beryllium - Precautions, Beryllium - Health effects

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Protactinium was first identified in 1913, when Kasimir Fajans and O. H. Göhring encountered short-lived isotope 234m-Pa, with a half-life of about 1.17 minutes, during their studies of the decay chain of 238-U. They gave the new element the name Brevium (Latin brevis, brief, short); the name was changed to Protoactinium in 1918 when two groups of scientists (Otto Hahn and Lise Meitner of Germany and Frederick Soddy and John Cranston of the UK) independently discovered 231-Pa, and s ...

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Protactinium, Protactinium - Notable Characteristics, Protactinium - Applications, Protactinium - History, Protactinium - Biological Role, Protactinium - Occurrence, Protactinium - Compounds, Protactinium - Isotopes, Protactinium - Precautions

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Acetic acid is produced both synthetically and by bacterial fermentation. Today, the biological route accounts for only about 10% of world production, but it remains important for vinegar production, as in much of the world food purity laws stipulate that vinegar used in foods must be of biological origin. About 75% of acetic acid made for use in the chemical industry is made by methanol carbonylation, explained below. Alternative methods account for the rest.^{See also:}

Acetic acid, Acetic acid - Nomenclature, Acetic acid - History, Acetic acid - Chemical properties, Acetic acid - Biochemistry, Acetic acid - Production, Acetic acid - Methanol carbonylation, Acetic acid - Acetaldehyde oxidation, Acetic acid - Ethylene oxidation, Acetic acid - Fermentation, Acetic acid - Applications, Acetic acid - Vinyl acetate monomer, Acetic acid - Acetic anhydride, Acetic acid - Ester production, Acetic acid - Vinegar, Acetic acid - Use as solvent, Acetic acid - Other applications, Acetic acid - Safety

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Scientists believe that the Earth formed from the same cloud of matter that formed the Sun. Abundance of the chemical elements - Abundance of elements in Earth's crust. The graphic below illustrates the relative abundance of the chemical elements in Earth's upper continental crust. Many of the elements shown in the graphic are classified into (partially overlapping) categories: rock-forming elements (major elements in green field and minor elements in light green field); ...

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Abundance of the chemical elements, Abundance of the chemical elements - Abundance of elements in the Universe, Abundance of the chemical elements - Abundance of elements in the Solar System, Abundance of the chemical elements - Abundance of elements in Earth, Abundance of the chemical elements - Abundance of elements in Earth's crust, Abundance of the chemical elements - Ocean, Abundance of the chemical elements - Atmosphere, Abundance of the chemical elements - Organisms, Abundance of the chemical elements - Human body

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In the United States and Europe there are a few "radon spas," where people sit for minutes or hours in a high-radon atmosphere in the belief that airborne radiation will invigorate or energize them. There is no scientific evidence for this belief, nor any known biological mechanism by which such an effect could occur. Because of radon's rapid loss to air, radon is used in hydrologic research that studies the interaction between ground water, streams and rivers. Any significant concentration of radon in a stream or river is a good indicator that t ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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Essentially chemically inert, but radioactive, radon is the heaviest noble gas and one of the heaviest gases at room temperature. (The heaviest is Uranium hexafluoride, UF6.) At standard temperature and pressure radon is a colorless gas but when it is cooled below its freezing point it has a brilliant phosphorescence which turns yellow as the temperature is lowered and orange-red at the temperature air liquefies. Natural radon concentrations in Earth's atmosphere are so low that natural waters in contact with the atmosphere ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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Radon (named for radium) was discovered in 1900 by Friedrich Ernst Dorn, who called it radium emanation. In 1908 William Ramsay and Robert Whytlaw-Gray, who named it niton (Latin nitens meaning "shining"; symbol Nt), isolated it, determined its density and that it was the heaviest known gas. It has been called radon since 1923. The danger of radon exposure in dwellings was discovered in 1984 by Stanley Watras, an employee at the Limerick nuclear power plant in Pennsylvania. Mr. Watras set off the radiation alarms on his ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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On average, there is one atom of radon in 1 x 1021 molecules of air. Radon can be found in some spring waters and hot springs. The towns of Misasa, Japan, and Bad Kreuznach, Germany boast radium-rich springs which emit radon. Radon exhausts naturally from the ground, particularly in certain regions, especially but not only regions with granitic soils. Not all granitic regions are prone to high emissions of radon. Depending on how houses are built and ventilated, radon may accumulate in basements and dwellings. The European ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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Hydrogen is the most abundant element in the known Universe; helium is second. However, after this, the rank of abundance does not continue to correspond to the atomic number; oxygen has abundance rank 3, but atomic number 8. All others are orders of magnitude less common. Both helium-3 and helium-4 were produced in the Big Bang. Additional helium is produced by the fusion of hydrogen inside stellar cores, via a process called the proton-proton chain. Hydrogen and helium are estimated to make up roughly 80% and 20% of all the m ...

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Abundance of the chemical elements, Abundance of the chemical elements - Abundance of elements in the Universe, Abundance of the chemical elements - Abundance of elements in the Solar System, Abundance of the chemical elements - Abundance of elements in Earth, Abundance of the chemical elements - Abundance of elements in Earth's crust, Abundance of the chemical elements - Ocean, Abundance of the chemical elements - Atmosphere, Abundance of the chemical elements - Organisms, Abundance of the chemical elements - Human body

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The Solar System was created from the remnants of previous stellar systems that went supernova, and is hence, relative to the rest of the universe, richer in heavier elements. Population I stars contain significant amounts of elements heavier than helium ("metals", in the terminology of astronomers). These heavy elements were produced by earlier generations of stars and spread by supernova explosions ...

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Abundance of the chemical elements, Abundance of the chemical elements - Abundance of elements in the Universe, Abundance of the chemical elements - Abundance of elements in the Solar System, Abundance of the chemical elements - Abundance of elements in Earth, Abundance of the chemical elements - Abundance of elements in Earth's crust, Abundance of the chemical elements - Ocean, Abundance of the chemical elements - Atmosphere, Abundance of the chemical elements - Organisms, Abundance of the chemical elements - Human body

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There are twenty known isotopes of radon. The most stable isotope is radon-222, which is a decay product (daughter product) of radium-226, has a half-life of 3.823 days and emits radioactive alpha particles. Radon-220 is a natural decay product of thorium and is called thoron. It has a half-life of 55.6 seconds and also emits alpha rays. Radon-219 is derived from actinium, is called actinon, is an alpha emitter an ...

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Radon, Radon - Notable characteristics, Radon - Applications, Radon - History, Radon - Occurrence, Radon - Compounds, Radon - Isotopes, Radon - Precautions, Radon - Radon therapy

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