Cobalt(II) oxide is an inorganic compound that has been described as an olive-green or gray solid . It is used extensively in the ceramics industry as an additive to create blue-colored glazes and enamels , as well as in the chemical industry for producing cobalt(II) salts. A related material is cobalt(II,III) oxide , a black solid with the formula Co 3 O 4 .
18-517: CoO crystals adopt the periclase ( rock salt ) structure with a lattice constant of 4.2615 Å. It is antiferromagnetic below 289 K. Cobalt(II) oxide is prepared by oxidation of cobalt powder with air or by thermal decomposition of cobalt(II) nitrate or the carbonate. Cobalt(II,III) oxide decomposes to cobalt(II) oxide at 950 °C: It may also be prepared by precipitating the hydroxide, followed by thermal dehydration: As can be expected, cobalt(II) oxide reacts with mineral acids to form
36-495: A consequence, the physical properties of periclase are well known, which makes the mineral a popular standard in experimental work. The mineral has been shown to remain stable at pressures up to at least 360 GPa . Ferropericlase (Mg,Fe)O makes up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO 3 ; it also
54-467: Is a cubic form of magnesium oxide ( Mg O ). In nature it usually forms a solid solution with wüstite (FeO) and is then referred to as ferropericlase or magnesiowüstite. It was first described in 1840 and named from the Greek περικλάω (to break around) in allusion to its cleavage. The type locality is Monte Somma , Somma- Vesuvius Complex, Naples Province , Campania , Italy . The old term for
72-463: Is also used to quantify internal pressure , stress , Young's modulus , and ultimate tensile strength . The unit, named after Blaise Pascal , is an SI coherent derived unit defined as one newton per square metre (N/m ). It is also equivalent to 10 barye (10 Ba) in the CGS system. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar , and
90-504: Is measured at 50 Pa. In medicine, blood pressure is measured in millimeters of mercury (mmHg, very close to one Torr ). The normal adult blood pressure is less than 120 mmHg systolic BP (SBP) and less than 80 mmHg diastolic BP (DBP). Convert mmHg to SI units as follows: 1 mmHg = 0.133 32 kPa . Hence normal blood pressure in SI units is less than 16.0 kPa SBP and less than 10.7 kPa DBP. These values are similar to
108-902: Is reported from Predazzo , Trentino , Italy ; Carlingford, County Louth , Ireland; Broadford, Skye and the island of Muck , Scotland; León , Spain; the Bellerberg Volcano , Eifel district, Germany; Nordmark and Långban , Varmland , Sweden ; and Kopeysk , southern Ural Mountains , Russia. In the US it occurs at the Crestmore quarry, Riverside County, California ; Tombstone, Arizona ; Gabbs district, Nye County, Nevada . In Canada , it occurs at Oka , Quebec and in Australia , west of Cowell , Eyre Peninsula , South Australia . The crystal structure of periclase corresponds to that of halite and has been studied extensively due to its simplicity. As
126-458: Is the newton , m is the metre , kg is the kilogram , s is the second , and J is the joule . One pascal is the pressure exerted by a force of one newton perpendicularly upon an area of one square metre. The unit of measurement called an atmosphere or a standard atmosphere (atm) is 101 325 Pa (101.325 kPa). This value is often used as a reference pressure and specified as such in some national and international standards, such as
144-500: Is the major host for iron in the lower mantle. At the bottom of the transition zone of the mantle, the reaction transforms γ-olivine into a mixture of perovskite and ferropericlase and vice versa . In the literature, this mineral phase of the lower mantle is also often called magnesiowüstite . Pascal (unit) The pascal (symbol: Pa ) is the unit of pressure in the International System of Units (SI) . It
162-420: Is used to measure sound pressure . Loudness is the subjective experience of sound pressure and is measured as a sound pressure level (SPL) on a logarithmic scale of the sound pressure relative to some reference pressure. For sound in air, a pressure of 20 μPa is considered to be at the threshold of hearing for humans and is a common reference pressure, so that its SPL is zero. The airtightness of buildings
180-465: The CJK Compatibility block, but these exist only for backward-compatibility with some older ideographic character-sets and are therefore deprecated . The pascal (Pa) or kilopascal (kPa) as a unit of pressure measurement is widely used throughout the world and has largely replaced the pounds per square inch (psi) unit, except in some countries that still use the imperial measurement system or
198-521: The International Organization for Standardization 's ISO 2787 (pneumatic tools and compressors), ISO 2533 (aerospace) and ISO 5024 (petroleum). In contrast, International Union of Pure and Applied Chemistry (IUPAC) recommends the use of 100 kPa as a standard pressure when reporting the properties of substances. Unicode has dedicated code-points U+33A9 ㎩ SQUARE PA and U+33AA ㎪ SQUARE KPA in
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#1732877084659216-619: The US customary system , including the United States. Geophysicists use the gigapascal (GPa) in measuring or calculating tectonic stresses and pressures within the Earth . Medical elastography measures tissue stiffness non-invasively with ultrasound or magnetic resonance imaging , and often displays the Young's modulus or shear modulus of tissue in kilopascals. In materials science and engineering ,
234-533: The United States typically use inches of mercury or millibars (hectopascals). In Canada, these reports are given in kilopascals. The unit is named after Blaise Pascal , noted for his contributions to hydrodynamics and hydrostatics, and experiments with a barometer . The name pascal was adopted for the SI unit newton per square metre (N/m ) by the 14th General Conference on Weights and Measures in 1971. The pascal can be expressed using SI derived units , or alternatively solely SI base units , as: where N
252-441: The corresponding cobalt salts: Cobalt(II) oxide has for centuries been used as a coloring agent on kiln fired pottery. The additive provides a deep shade of blue named cobalt blue . The band gap (CoO) is around 2.4 eV. It also is used in cobalt blue glass . Periclase Periclase is a magnesium mineral that occurs naturally in contact metamorphic rocks and is a major component of most basic refractory bricks. It
270-503: The kilopascal (1 kPa = 1000 Pa), which is equal to one centibar. The unit of measurement called standard atmosphere (atm) is defined as 101 325 Pa . Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization , thus a standard atmosphere (atm) or typical sea-level air pressure is about 1013 hPa. Reports in
288-615: The mineral is magnesia . Stones from the Magnesia region in ancient Anatolia contained both magnesium oxide and hydrated magnesium carbonate as well as iron oxides (such as magnetite ). Thus these stones, called Stones from Magnesia in antiquity, with their unusual magnetic properties were the reason the terms magnet and magnetism were coined. Periclase is usually found in marble produced by metamorphism of dolomitic limestones . It readily alters to brucite under near surface conditions. In addition to its type locality, it
306-483: The pascal measures the stiffness , tensile strength and compressive strength of materials. In engineering the megapascal (MPa) is the preferred unit for these uses, because the pascal represents a very small quantity. The pascal is also equivalent to the SI unit of energy density , the joule per cubic metre. This applies not only to the thermodynamics of pressurised gases, but also to the energy density of electric , magnetic , and gravitational fields. The pascal
324-567: The pressure of water column of average human height; so pressure has to be measured on arm roughly at the level of the heart. The units of atmospheric pressure commonly used in meteorology were formerly the bar (100,000 Pa), which is close to the average air pressure on Earth, and the millibar. Since the introduction of SI units , meteorologists generally measure pressures in hectopascals (hPa) unit, equal to 100 pascals or 1 millibar. Exceptions include Canada, which uses kilopascals (kPa). In many other fields of science, prefixes that are
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