107-718: Potassium ( 19 K ) has 25 known isotopes from K to K as well as K , as well as an unconfirmed report of K . Three of those isotopes occur naturally: the two stable forms K (93.3%) and K (6.7%), and a very long-lived radioisotope K (0.012%) Naturally occurring radioactive K decays with a half-life of 1.248×10 years. 89% of those decays are to stable Ca by beta decay , whilst 11% are to Ar by either electron capture or positron emission . This latter decay branch has produced an isotopic abundance of argon on Earth which differs greatly from that seen in gas giants and stellar spectra. K has
214-472: A coolant in the rotor and the stator in 1937 at Dayton , Ohio, owned by the Dayton Power & Light Co. This was justified by the high thermal conductivity and very low viscosity of hydrogen gas, thus lower drag than air. This is the most common coolant used for generators 60 MW and larger; smaller generators are usually air-cooled . The nickel–hydrogen battery was used for the first time in 1977 aboard
321-465: A nucleus which is usually composed of one proton. That is why H is often called a proton. This species is central to discussion of acids . Under the Brønsted–Lowry acid–base theory , acids are proton donors, while bases are proton acceptors. A bare proton, H , cannot exist in solution or in ionic crystals because of its strong attraction to other atoms or molecules with electrons. Except at
428-405: A pot the ash of burnt wood or tree leaves, adding water, heating, and evaporating the solution. When Humphry Davy first isolated the pure element using electrolysis in 1807, he named it potassium , which he derived from the word potash . The symbol K stems from kali , itself from the root word alkali , which in turn comes from Arabic : القَلْيَه al-qalyah 'plant ashes'. In 1797,
535-416: A radioactive source for classroom demonstrations. K is the largest source of natural radioactivity in healthy animals and humans, greater even than C . In a human body of 70 kg mass, about 4,400 nuclei of K decay per second. The decay of K to Ar is used in potassium-argon dating of rocks. Minerals are dated by measurement of the concentration of potassium and
642-490: A stoichiometric quantity of hydrogen at the anode. For hydrides other than group 1 and 2 metals, the term is quite misleading, considering the low electronegativity of hydrogen. An exception in group 2 hydrides is BeH 2 , which is polymeric. In lithium aluminium hydride , the [AlH 4 ] anion carries hydridic centers firmly attached to the Al(III). Although hydrides can be formed with almost all main-group elements,
749-437: A fire. Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions: Many metals such as zirconium undergo a similar reaction with water leading to the production of hydrogen. François Isaac de Rivaz built the first de Rivaz engine , an internal combustion engine powered by a mixture of hydrogen and oxygen in 1806. Edward Daniel Clarke invented
856-400: A human body of 70 kg, about 4,400 nuclei of K decay per second. The activity of natural potassium is 31 Bq /g. Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition
963-448: A monatomic gas at cryogenic temperatures. According to quantum theory, this behavior arises from the spacing of the (quantized) rotational energy levels, which are particularly wide-spaced in H 2 because of its low mass. These widely spaced levels inhibit equal partition of heat energy into rotational motion in hydrogen at low temperatures. Diatomic gases composed of heavier atoms do not have such widely spaced levels and do not exhibit
1070-545: A partial negative charge. These compounds are often known as hydrides . Hydrogen forms many compounds with carbon called the hydrocarbons , and even more with heteroatoms that, due to their association with living things, are called organic compounds . The study of their properties is known as organic chemistry and their study in the context of living organisms is called biochemistry . By some definitions, "organic" compounds are only required to contain carbon. However, most of them also contain hydrogen, and because it
1177-477: A partial positive charge. When bonded to a more electronegative element, particularly fluorine , oxygen , or nitrogen , hydrogen can participate in a form of medium-strength noncovalent bonding with another electronegative element with a lone pair, a phenomenon called hydrogen bonding that is critical to the stability of many biological molecules. Hydrogen also forms compounds with less electronegative elements, such as metals and metalloids , where it takes on
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#17330852505841284-400: A plant salt, by a similar technique, demonstrating that the elements, and thus the salts, are different. Although the production of potassium and sodium metal should have shown that both are elements, it took some time before this view was universally accepted. Because of the sensitivity of potassium to water and air, air-free techniques are normally employed for handling the element. It
1391-405: A proton and an electron, the hydrogen atom , together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. Furthermore, study of the corresponding simplicity of the hydrogen molecule and the corresponding cation H + 2 brought understanding of the nature of the chemical bond , which followed shortly after
1498-526: A serious incident. Hydrogen-lifted airships were used as observation platforms and bombers during the war. The first non-stop transatlantic crossing was made by the British airship R34 in 1919. Regular passenger service resumed in the 1920s and the discovery of helium reserves in the United States promised increased safety, but the U.S. government refused to sell the gas for this purpose. Therefore, H 2
1605-440: A similar experiment with iron and sulfuric acid. However, in all likelihood, "sulfureous" should here be understood to mean "combustible". In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "inflammable air". He speculated that "inflammable air" was in fact identical to the hypothetical substance " phlogiston " and further finding in 1781 that
1712-498: A smaller portion comes from energy-intensive methods such as the electrolysis of water . Its main industrial uses include fossil fuel processing, such as hydrocracking , and ammonia production , with emerging uses in fuel cells for electricity generation and as a heat source. When used in fuel cells, hydrogen's only emission at point of use is water vapor, though combustion can produce nitrogen oxides . Hydrogen's interaction with metals may cause embrittlement . Hydrogen gas
1819-467: A spark or flame, they do not react at room temperature in the absence of a catalyst. The ground state energy level of the electron in a hydrogen atom is −13.6 eV , equivalent to an ultraviolet photon of roughly 91 nm wavelength. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, in which the electron "orbits" the proton, like how Earth orbits
1926-450: A species. To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the " hydronium ion" ( [H 3 O] ). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into clusters that form species closer to [H 9 O 4 ] . Other oxonium ions are found when water
2033-406: A spin singlet state having spin S = 0 {\displaystyle S=0} . The equilibrium ratio of ortho- to para-hydrogen depends on temperature. At room temperature or warmer, equilibrium hydrogen gas contains about 25% of the para form and 75% of the ortho form. The ortho form is an excited state , having higher energy than the para form by 1.455 kJ/mol, and it converts to
2140-438: A term that is used fairly loosely. The term "hydride" suggests that the H atom has acquired a negative or anionic character, denoted H ; and is used when hydrogen forms a compound with a more electropositive element. The existence of the hydride anion , suggested by Gilbert N. Lewis in 1916 for group 1 and 2 salt-like hydrides, was demonstrated by Moers in 1920 by the electrolysis of molten lithium hydride (LiH), producing
2247-486: A variety of graphite intercalation compounds , including KC 8 . There are 25 known isotopes of potassium, three of which occur naturally: K (93.3%), K (0.0117%), and K (6.7%) (by mole fraction). Naturally occurring K has a half-life of 1.250 × 10 years. It decays to stable Ar by electron capture or positron emission (11.2%) or to stable Ca by beta decay (88.8%). The decay of K to Ar
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#17330852505842354-478: A while before caus'd to be purposely fil'd off from a piece of good steel. This metalline powder being moistn'd in the viol with a little of the menstruum, was afterwards drench'd with more; whereupon the mixture grew very hot, and belch'd up copious and stinking fumes; which whether they consisted altogether of the volatile sulfur of the Mars [iron], or of metalline steams participating of a sulfureous nature, and join'd with
2461-477: A wide variety of proteins and enzymes. Potassium levels influence multiple physiological processes, including Potassium homeostasis denotes the maintenance of the total body potassium content, plasma potassium level, and the ratio of the intracellular to extracellular potassium concentrations within narrow limits, in the face of pulsatile intake (meals), obligatory renal excretion, and shifts between intracellular and extracellular compartments. Plasma potassium
2568-418: Is K , a three- proton emitter discovered in 2019; its half-life was measured to be shorter than 10 picoseconds . Stable potassium isotopes have been used for several nutrient cycling studies since potassium is a macronutrient required for life . Potassium Potassium is a chemical element ; it has symbol K (from Neo-Latin kalium ) and atomic number 19. It
2675-579: Is exothermic and produces enough heat to evaporate most of the liquid if not converted first to parahydrogen during the cooling process. Catalysts for the ortho-para interconversion, such as ferric oxide and activated carbon compounds, are used during hydrogen cooling to avoid this loss of liquid. While H 2 is not very reactive under standard conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative , such as halogens (F, Cl, Br, I), or oxygen ; in these compounds hydrogen takes on
2782-418: Is potassium cobaltinitrite , K 3 [Co(NO 2 ) 6 ] , which is used as artist's pigment under the name of Aureolin or Cobalt Yellow. The stable isotopes of potassium can be laser cooled and used to probe fundamental and technological problems in quantum physics . The two bosonic isotopes possess convenient Feshbach resonances to enable studies requiring tunable interactions, while K
2889-448: Is 0.04% potassium by weight), and occurs in many minerals such as orthoclase , a common constituent of granites and other igneous rocks . Potassium is chemically very similar to sodium , the previous element in group 1 of the periodic table. They have a similar first ionization energy , which allows for each atom to give up its sole outer electron. It was first suggested in 1702 that they were distinct elements that combine with
2996-469: Is a macronutrient required for life on Earth. K occurs in natural potassium (and thus in some commercial salt substitutes) in sufficient quantity that large bags of those substitutes can be used as a radioactive source for classroom demonstrations. K is the radioisotope with the largest abundance in the human body . In healthy animals and people, K represents the largest source of radioactivity, greater even than C . In
3103-493: Is a strong base . Illustrating its hydrophilic character, as much as 1.21 kg of KOH can dissolve in a single liter of water. Anhydrous KOH is rarely encountered. KOH reacts readily with carbon dioxide ( CO 2 ) to produce potassium carbonate ( K 2 CO 3 ), and in principle could be used to remove traces of the gas from air. Like the closely related sodium hydroxide , KOH reacts with fats to produce soaps . In general, potassium compounds are ionic and, owing to
3210-406: Is a main constituent of some varieties of baking powder ; it is also used in the silvering of mirrors. Potassium bromate ( KBrO 3 ) is a strong oxidizer (E924), used to improve dough strength and rise height. Potassium bisulfite ( KHSO 3 ) is used as a food preservative, for example in wine and beer -making (but not in meats). It is also used to bleach textiles and straw, and in
3317-454: Is a necessary element for plants and that most types of soil lack potassium caused a steep rise in demand for potassium salts. Wood-ash from fir trees was initially used as a potassium salt source for fertilizer, but, with the discovery in 1868 of mineral deposits containing potassium chloride near Staßfurt , Germany, the production of potassium-containing fertilizers began at an industrial scale. Other potash deposits were discovered, and by
Isotopes of potassium - Misplaced Pages Continue
3424-402: Is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash , the ashes of plants, from which its name derives. In the periodic table , potassium is one of the alkali metals , all of which have a single valence electron in
3531-668: Is accelerated by minute amounts of transition metal salts. Because it can reduce the salts to the metal, potassium is often used as the reductant in the preparation of finely divided metals from their salts by the Rieke method . Illustrative is the preparation of magnesium: Potassium is formed in supernovae by nucleosynthesis from lighter atoms. Potassium is principally created in Type II supernovae via an explosive oxygen-burning process . These are nuclear fusion reactions, not to be confused with chemical burning of potassium in oxygen. K
3638-516: Is also formed in s-process nucleosynthesis and the neon burning process . Potassium is the 20th most abundant element in the solar system and the 17th most abundant element by weight in the Earth. It makes up about 2.6% of the weight of the Earth's crust and is the seventh most abundant element in the crust. The potassium concentration in seawater is 0.39 g/L (0.039 wt/v%), about one twenty-seventh
3745-448: Is also used in organic synthesis to make nitriles . Potassium carbonate ( K 2 CO 3 or potash) is used in the manufacture of glass, soap, color TV tubes, fluorescent lamps, textile dyes and pigments. Potassium permanganate ( KMnO 4 ) is an oxidizing, bleaching and purification substance and is used for production of saccharin . Potassium chlorate ( KClO 3 ) is added to matches and explosives. Potassium bromide (KBr)
3852-433: Is also used in some mines. The resulting sodium and magnesium waste is either stored underground or piled up in slag heaps . Most of the mined potassium mineral ends up as potassium chloride after processing. The mineral industry refers to potassium chloride either as potash, muriate of potash, or simply MOP. Pure potassium metal can be isolated by electrolysis of its hydroxide in a process that has changed little since it
3959-505: Is crucial in acid-base reactions , which mainly involve proton exchange among soluble molecules. In ionic compounds , hydrogen can take the form of either a negatively charged anion , where it is known as hydride , or as a positively charged cation , H . The cation, usually just a proton (symbol p ), exhibits specific behavior in aqueous solutions and in ionic compounds involves screening of its electric charge by surrounding polar molecules or anions. Hydrogen's unique position as
4066-416: Is detected in order to probe primordial hydrogen. The large amount of neutral hydrogen found in the damped Lyman-alpha systems is thought to dominate the cosmological baryonic density of the universe up to a redshift of z = 4. Under ordinary conditions on Earth, elemental hydrogen exists as the diatomic gas, H 2 . Hydrogen gas is very rare in Earth's atmosphere (around 0.53 ppm on
4173-400: Is highly flammable: Enthalpy of combustion : −286 kJ/mol. Hydrogen gas forms explosive mixtures with air in concentrations from 4–74% and with chlorine at 5–95%. The hydrogen autoignition temperature , the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to
4280-507: Is illustrative: The potassium cobaltinitrite is obtained as a yellow solid. Potassium ions are an essential component of plant nutrition and are found in most soil types. They are used as a fertilizer in agriculture , horticulture , and hydroponic culture in the form of chloride (KCl), sulfate ( K 2 SO 4 ), or nitrate ( KNO 3 ), representing the 'K' in 'NPK' . Agricultural fertilizers consume 95% of global potassium chemical production, and about 90% of this potassium
4387-453: Is in acidic solution with other solvents. Although exotic on Earth, one of the most common ions in the universe is the H + 3 ion, known as protonated molecular hydrogen or the trihydrogen cation. Hydrogen has three naturally occurring isotopes, denoted H , H and H . Other, highly unstable nuclei ( H to H ) have been synthesized in the laboratory but not observed in nature. Unique among
Isotopes of potassium - Misplaced Pages Continue
4494-570: Is mined in Canada , Russia , Belarus , Kazakhstan , Germany , Israel , the U.S., Jordan , and other places around the world. The first mined deposits were located near Staßfurt, Germany, but the deposits span from Great Britain over Germany into Poland. They are located in the Zechstein and were deposited in the Middle to Late Permian . The largest deposits ever found lie 1,000 meters (3,300 feet) below
4601-457: Is necessary for normal nerve transmission; potassium deficiency and excess can each result in numerous signs and symptoms, including an abnormal heart rhythm and various electrocardiographic abnormalities. Fresh fruits and vegetables are good dietary sources of potassium. The body responds to the influx of dietary potassium, which raises serum potassium levels, by shifting potassium from outside to inside cells and increasing potassium excretion by
4708-447: Is normally kept at 3.5 to 5.5 millimoles (mmol) [or milliequivalents (mEq)] per liter by multiple mechanisms. Levels outside this range are associated with an increasing rate of death from multiple causes, and some cardiac, kidney, and lung diseases progress more rapidly if serum potassium levels are not maintained within the normal range. Hydrogen Hydrogen is a chemical element ; it has symbol H and atomic number 1. It
4815-494: Is obtained from natural sources such as guano and evaporites or manufactured via the Haber process ; it is the oxidant in gunpowder ( black powder ) and an important agricultural fertilizer. Potassium cyanide (KCN) is used industrially to dissolve copper and precious metals, in particular silver and gold , by forming complexes . Its applications include gold mining , electroplating , and electroforming of these metals ; it
4922-401: Is one of only two stable fermions amongst the alkali metals. An alloy of sodium and potassium, NaK is a liquid used as a heat-transfer medium and a desiccant for producing dry and air-free solvents . It can also be used in reactive distillation . The ternary alloy of 12% Na, 47% K and 41% Cs has the lowest melting point of −78 °C of any metallic compound. Metallic potassium
5029-429: Is produced mostly by decomposition of the complex minerals kainite ( MgSO 4 ·KCl·3H 2 O ) and langbeinite ( MgSO 4 ·K 2 SO 4 ). Only a very few fertilizers contain potassium nitrate. In 2005, about 93% of world potassium production was consumed by the fertilizer industry. Furthermore, potassium can play a key role in nutrient cycling by controlling litter composition. Potassium citrate
5136-484: Is soluble in both nanocrystalline and amorphous metals . Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice . These properties may be useful when hydrogen is purified by passage through hot palladium disks, but the gas's high solubility is a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks. Hydrogen compounds are often called hydrides ,
5243-532: Is still used, in preference to non-flammable but more expensive helium, as a lifting gas for weather balloons . Deuterium was discovered in December 1931 by Harold Urey , and tritium was prepared in 1934 by Ernest Rutherford , Mark Oliphant , and Paul Harteck . Heavy water , which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. The first hydrogen-cooled turbogenerator went into service using gaseous hydrogen as
5350-435: Is supplied as KCl. The potassium content of most plants ranges from 0.5% to 2% of the harvested weight of crops, conventionally expressed as amount of K 2 O . Modern high- yield agriculture depends upon fertilizers to replace the potassium lost at harvest. Most agricultural fertilizers contain potassium chloride, while potassium sulfate is used for chloride-sensitive crops or crops needing higher sulfur content. The sulfate
5457-770: Is the basis of a common method for dating rocks. The conventional K-Ar dating method depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon ( Ar ) was quantitatively retained. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic Ar that has accumulated. The minerals best suited for dating include biotite , muscovite , metamorphic hornblende , and volcanic feldspar ; whole rock samples from volcanic flows and shallow instrusives can also be dated if they are unaltered. Apart from dating, potassium isotopes have been used as tracers in studies of weathering and for nutrient cycling studies because potassium
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#17330852505845564-412: Is the carbon-hydrogen bond that gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. Millions of hydrocarbons are known, and they are usually formed by complicated pathways that seldom involve elemental hydrogen. Hydrogen is highly soluble in many rare earth and transition metals and
5671-400: Is the lightest element and, at standard conditions , is a gas of diatomic molecules with the formula H 2 , sometimes called dihydrogen , but more commonly called hydrogen gas , molecular hydrogen or simply hydrogen. It is colorless, odorless, non-toxic, and highly combustible . Constituting about 75% of all normal matter , hydrogen is the most abundant chemical element in
5778-410: Is unreactive toward nitrogen and saturated hydrocarbons such as mineral oil or kerosene . It readily dissolves in liquid ammonia , up to 480 g per 1000 g of ammonia at 0 °C. Depending on the concentration, the ammonia solutions are blue to yellow, and their electrical conductivity is similar to that of liquid metals. Potassium slowly reacts with ammonia to form KNH 2 , but this reaction
5885-415: Is used in several types of magnetometers . Potassium is the eighth or ninth most common element by mass (0.2%) in the human body, so that a 60 kg adult contains a total of about 120 g of potassium. The body has about as much potassium as sulfur and chlorine, and only calcium and phosphorus are more abundant (with the exception of the ubiquitous CHON elements). Potassium ions are present in
5992-410: Is used to treat a kidney stone condition called renal tubular acidosis . Potassium, in the form of potassium chloride is used as a medication to treat and prevent low blood potassium . Low blood potassium may occur due to vomiting , diarrhea , or certain medications. It is given by slow injection into a vein or by mouth. Potassium sodium tartrate ( KNaC 4 H 4 O 6 , Rochelle salt )
6099-455: The Dead Sea is used by Israel and Jordan as a source of potash, while the concentration in normal oceans is too low for commercial production at current prices. Several methods are used to separate potassium salts from sodium and magnesium compounds. The most-used method is fractional precipitation using the solubility differences of the salts. Electrostatic separation of the ground salt mixture
6206-496: The Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated. The visible flames in the photographs were the result of carbon compounds in the airship skin burning. H 2 is unreactive compared to diatomic elements such as halogens or oxygen. The thermodynamic basis of this low reactivity is the very strong H–H bond, with a bond dissociation energy of 435.7 kJ/mol. The kinetic basis of
6313-570: The International Union of Pure and Applied Chemistry (IUPAC) allows any of D, T, H , and H to be used, though H and H are preferred. The exotic atom muonium (symbol Mu), composed of an anti muon and an electron , can also be considered a light radioisotope of hydrogen. Because muons decay with lifetime 2.2 µs , muonium is too unstable for observable chemistry. Nevertheless, muonium compounds are important test cases for quantum simulation , due to
6420-411: The chromate ion rather than to that of the potassium ion. There are thousands of uses of various potassium compounds. One example is potassium superoxide , KO 2 , an orange solid that acts as a portable source of oxygen and a carbon dioxide absorber. It is widely used in respiration systems in mines, submarines and spacecraft as it takes less volume than the gaseous oxygen. Another example
6527-444: The universe . Stars , including the Sun , mainly consist of hydrogen in a plasma state , while on Earth, hydrogen is found in water , organic compounds , as dihydrogen , and in other molecular forms . The most common isotope of hydrogen (protium, H) consists of one proton , one electron , and no neutrons . In the early universe , the formation of hydrogen's protons occurred in
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#17330852505846634-431: The "planetary orbit" differs from electron motion. Molecular H 2 exists as two spin isomers , i.e. compounds that differ only in the spin states of their nuclei. In the orthohydrogen form, the spins of the two nuclei are parallel, forming a spin triplet state having a total molecular spin S = 1 {\displaystyle S=1} ; in the parahydrogen form the spins are antiparallel and form
6741-424: The 1960s Canada became the dominant producer. Potassium metal was first isolated in 1807 by Humphry Davy, who derived it by electrolysis of molten caustic potash (KOH) with the newly discovered voltaic pile . Potassium was the first metal that was isolated by electrolysis. Later in the same year, Davy reported extraction of the metal sodium from a mineral derivative ( caustic soda , NaOH, or lye) rather than
6848-582: The German chemist Martin Klaproth discovered "potash" in the minerals leucite and lepidolite , and realized that "potash" was not a product of plant growth but actually contained a new element, which he proposed calling kali . In 1807, Humphry Davy produced the element via electrolysis: in 1809, Ludwig Wilhelm Gilbert proposed the name Kalium for Davy's "potassium". In 1814, the Swedish chemist Berzelius advocated
6955-476: The Sun and other stars). The charged particles are highly influenced by magnetic and electric fields. For example, in the solar wind they interact with the Earth's magnetosphere giving rise to Birkeland currents and the aurora . Hydrogen is found in the neutral atomic state in the interstellar medium because the atoms seldom collide and combine. They are the source of the 21-cm hydrogen line at 1420 MHz that
7062-454: The Sun and the CNO cycle of nuclear fusion in case of stars more massive than the Sun . Throughout the universe, hydrogen is mostly found in the atomic and plasma states, with properties quite distinct from those of molecular hydrogen. As a plasma, hydrogen's electron and proton are not bound together, resulting in very high electrical conductivity and high emissivity (producing the light from
7169-460: The Sun. However, the electron and proton are held together by electrostatic attraction, while planets and celestial objects are held by gravity . Due to the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. A more accurate description of
7276-641: The U.S. Navy's Navigation technology satellite-2 (NTS-2). The International Space Station , Mars Odyssey and the Mars Global Surveyor are equipped with nickel-hydrogen batteries. In the dark part of its orbit, the Hubble Space Telescope is also powered by nickel-hydrogen batteries, which were finally replaced in May 2009, more than 19 years after launch and 13 years beyond their design life. Because of its simple atomic structure, consisting only of
7383-434: The alkali in his list of chemical elements in 1789. For a long time the only significant applications for potash were the production of glass, bleach, soap and gunpowder as potassium nitrate. Potassium soaps from animal fats and vegetable oils were especially prized because they tend to be more water-soluble and of softer texture, and are therefore known as soft soaps. The discovery by Justus Liebig in 1840 that potassium
7490-411: The amount of radiogenic Ar that has accumulated. Typically, the method assumes that the rocks contained no argon at the time of formation and all subsequent radiogenic argon (i.e., Ar ) was retained. K has also been extensively used as a radioactive tracer in studies of weathering . All other potassium isotopes have half-lives under a day, most under a minute. The least stable
7597-513: The concentration of sodium. Elemental potassium does not occur in nature because of its high reactivity. It reacts violently with water and also reacts with oxygen. Orthoclase (potassium feldspar) is a common rock-forming mineral. Granite for example contains 5% potassium, which is well above the average in the Earth's crust. Sylvite (KCl), carnallite ( KCl·MgCl 2 ·6H 2 O ), kainite ( MgSO 4 ·KCl·3H 2 O ) and langbeinite ( MgSO 4 ·K 2 SO 4 ) are
7704-619: The configuration of the noble gas argon . Because of its low first ionization energy of 418.8 kJ/mol, the potassium atom is much more likely to lose the last electron and acquire a positive charge, although negatively charged alkalide K ions are not impossible. In contrast, the second ionization energy is very high (3052 kJ/mol). Potassium reacts with oxygen, water, and carbon dioxide components in air. With oxygen it forms potassium peroxide . With water potassium forms potassium hydroxide (KOH). The reaction of potassium with water can be violently exothermic , especially since
7811-450: The coproduced hydrogen gas can ignite. Because of this, potassium and the liquid sodium-potassium ( NaK ) alloy are potent desiccants , although they are no longer used as such. Four oxides of potassium are well studied: potassium oxide ( K 2 O ), potassium peroxide ( K 2 O 2 ), potassium superoxide ( KO 2 ) and potassium ozonide ( KO 3 ). The binary potassium-oxygen compounds react with water forming KOH. KOH
7918-430: The elements, distinct names are assigned to its isotopes in common use. During the early study of radioactivity, heavy radioisotopes were given their own names, but these are mostly no longer used. The symbols D and T (instead of H and H ) are sometimes used for deuterium and tritium, but the symbol P was already used for phosphorus and thus was not available for protium. In its nomenclatural guidelines,
8025-493: The first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard . German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen that later were called Zeppelins ; the first of which had its maiden flight in 1900. Regularly scheduled flights started in 1910 and by the outbreak of World War I in August 1914, they had carried 35,000 passengers without
8132-491: The first second after the Big Bang ; neutral hydrogen atoms only formed about 370,000 years later during the recombination epoch as the universe cooled and plasma had cooled enough for electrons to remain bound to protons. Hydrogen, typically nonmetallic except under extreme pressure , readily forms covalent bonds with most nonmetals, contributing to the formation of compounds like water and various organic substances. Its role
8239-608: The formation of a surface layer of potassium superoxide , a pressure-sensitive explosive that detonates when scratched. The resulting explosion often starts a fire difficult to extinguish. Potassium is now quantified by ionization techniques, but at one time it was quantitated by gravimetric analysis . Reagents used to precipitate potassium salts include sodium tetraphenylborate , hexachloroplatinic acid , and sodium cobaltinitrite into respectively potassium tetraphenylborate , potassium hexachloroplatinate , and potassium cobaltinitrite . The reaction with sodium cobaltinitrite
8346-462: The gas produces water when burned. He is usually given credit for the discovery of hydrogen as an element. In 1783, Antoine Lavoisier identified the element that came to be known as hydrogen when he and Laplace reproduced Cavendish's finding that water is produced when hydrogen is burned. Lavoisier produced hydrogen for his experiments on mass conservation by reacting a flux of steam with metallic iron through an incandescent iron tube heated in
8453-595: The high hydration energy of the K ion, have excellent water solubility. The main species in water solution are the aquo complexes [K(H 2 O) n ] where n = 6 and 7. Potassium heptafluorotantalate ( K 2 [TaF 7 ] ) is an intermediate in the purification of tantalum from the otherwise persistent contaminant of niobium . Organopotassium compounds illustrate nonionic compounds of potassium. They feature highly polar covalent K–C bonds. Examples include benzyl potassium KCH 2 C 6 H 5 . Potassium intercalates into graphite to give
8560-427: The high temperatures associated with plasmas, such protons cannot be removed from the electron clouds of atoms and molecules, and will remain attached to them. However, the term 'proton' is sometimes used loosely and metaphorically to refer to positively charged or cationic hydrogen attached to other species in this fashion, and as such is denoted " H " without any implication that any single protons exist freely as
8667-497: The hydrogen atom comes from a quantum analysis that uses the Schrödinger equation , Dirac equation or Feynman path integral formulation to calculate the probability density of the electron around the proton. The most complex formulas include the small effects of special relativity and vacuum polarization . In the quantum mechanical treatment, the electron in a ground state hydrogen atom has no angular momentum—illustrating how
8774-399: The hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823. Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask . He produced solid hydrogen the next year. The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for
8881-501: The kidneys. Most industrial applications of potassium exploit the high solubility of its compounds in water, such as saltwater soap . Heavy crop production rapidly depletes the soil of potassium, and this can be remedied with agricultural fertilizers containing potassium, accounting for 95% of global potassium chemical production. The English name for the element potassium comes from the word potash , which refers to an early method of extracting various potassium salts: placing in
8988-430: The longest known half-life for any positron-emitter nuclide . The long half-life of this primordial radioisotope is caused by a highly spin-forbidden transition : K has a nuclear spin of 4, while both of its decay daughters are even–even isotopes with spins of 0. K occurs in natural potassium in sufficient quantity that large bags of potassium chloride commercial salt substitutes can be used as
9095-400: The low reactivity is the nonpolar nature of H 2 and its weak polarizability. It spontaneously reacts with chlorine and fluorine to form hydrogen chloride and hydrogen fluoride , respectively. The reactivity of H 2 is strongly affected by the presence of metal catalysts. Thus, while mixtures of H 2 with O 2 or air combust readily when heated to at least 500°C by
9202-402: The mass difference between the antimuon and the proton, and IUPAC nomenclature incorporates such hypothetical compounds as muonium chloride (MuCl) and sodium muonide (NaMu), analogous to hydrogen chloride and sodium hydride respectively. Table of thermal and physical properties of hydrogen (H 2 ) at atmospheric pressure: In 1671, Irish scientist Robert Boyle discovered and described
9309-481: The mass of the universe, however, is not in the form of chemical-element type matter, but rather is postulated to occur as yet-undetected forms of mass such as dark matter and dark energy . Hydrogen is found in great abundance in stars and gas giant planets. Molecular clouds of H 2 are associated with star formation . Hydrogen plays a vital role in powering stars through the proton-proton reaction in case of stars with very low to approximately 1 mass of
9416-706: The minerals found in large evaporite deposits worldwide. The deposits often show layers starting with the least soluble at the bottom and the most soluble on top. Deposits of niter ( potassium nitrate ) are formed by decomposition of organic material in contact with atmosphere, mostly in caves; because of the good water solubility of niter the formation of larger deposits requires special environmental conditions. Potassium salts such as carnallite , langbeinite , polyhalite , and sylvite form extensive evaporite deposits in ancient lake bottoms and seabeds , making extraction of potassium salts in these environments commercially viable. The principal source of potassium – potash –
9523-490: The naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine , compared to the highly visible plume of a Space Shuttle Solid Rocket Booster , which uses an ammonium perchlorate composite . The detection of a burning hydrogen leak, may require a flame detector ; such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of
9630-412: The name kalium for potassium, with the chemical symbol K . The English and French-speaking countries adopted the name Potassium , which was favored by Davy and French chemists Joseph Louis Gay-Lussac and Louis Jacques Thénard , whereas the other Germanic countries adopted Gilbert and Klaproth's name Kalium . The "Gold Book" of the International Union of Pure and Applied Chemistry has designated
9737-649: The number and combination of possible compounds varies widely; for example, more than 100 binary borane hydrides are known, but only one binary aluminium hydride. Binary indium hydride has not yet been identified, although larger complexes exist. In inorganic chemistry , hydrides can also serve as bridging ligands that link two metal centers in a coordination complex . This function is particularly common in group 13 elements , especially in boranes ( boron hydrides) and aluminium complexes, as well as in clustered carboranes . Oxidation of hydrogen removes its electron and gives H , which contains no electrons and
9844-468: The official chemical symbol as K . Potassium is the second least dense metal after lithium . It is a soft solid with a low melting point , and can be easily cut with a knife. Potassium is silvery in appearance, but it begins to tarnish toward gray immediately on exposure to air. In a flame test , potassium and its compounds emit a lilac color with a peak emission wavelength of 766.5 nanometers. Neutral potassium atoms have 19 electrons, one more than
9951-651: The only neutral atom for which the Schrödinger equation can be directly solved, has significantly contributed to the foundational principles of quantum mechanics through the exploration of its energetics and chemical bonding . Hydrogen gas was first produced artificially in the early 16th century by reacting acids with metals. Henry Cavendish , in 1766–81, identified hydrogen gas as a distinct substance and discovered its property of producing water when burned; hence its name means "water-former" in Greek. Most hydrogen production occurs through steam reforming of natural gas ;
10058-401: The outer electron shell, which is easily removed to create an ion with a positive charge (which combines with anions to form salts ). In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac - colored flame . It is found dissolved in seawater (which
10165-420: The para form over the course of several minutes when cooled to low temperature. The thermal properties of the forms differ because they differ in their allowed rotational quantum states , resulting in different thermal properties such as the heat capacity. The ortho-to-para ratio in H 2 is an important consideration in the liquefaction and storage of liquid hydrogen : the conversion from ortho to para
10272-477: The quantum mechanical treatment of the hydrogen atom had been developed in the mid-1920s. One of the first quantum effects to be explicitly noticed (but not understood at the time) was a Maxwell observation involving hydrogen, half a century before full quantum mechanical theory arrived. Maxwell observed that the specific heat capacity of H 2 unaccountably departs from that of a diatomic gas below room temperature and begins to increasingly resemble that of
10379-502: The reaction between iron filings and dilute acids , which results in the production of hydrogen gas. Having provided a saline spirit [hydrochloric acid], which by an uncommon way of preparation was made exceeding sharp and piercing, we put into a vial, capable of containing three or four ounces of water, a convenient quantity of filings of steel, which were not such as are commonly sold in shops to Chymists and Apothecaries, (those being usually not free enough from rust) but such as I had
10486-418: The reaction of potassium fluoride with calcium carbide was also used to produce potassium. Reagent-grade potassium metal costs about $ 10.00/ pound ($ 22/ kg ) in 2010 when purchased by the tonne . Lower purity metal is considerably cheaper. The market is volatile because long-term storage of the metal is difficult. It must be stored in a dry inert gas atmosphere or anhydrous mineral oil to prevent
10593-506: The saline exhalations of the menstruum, is not necessary to be here discuss'd. But whencesoever this stinking smoak proceeded, so inflammable it was, that upon the approach of a lighted candle to it, it would readily enough take fire, and burn with a blewish and somewhat greenish flame at the mouth of the viol for a good while together; and that, though with little light, yet with more strength than one would easily suspect. The word "sulfureous" may be somewhat confusing, especially since Boyle did
10700-473: The same anions to make similar salts, which was demonstrated in 1807 when elemental potassium was first isolated via electrolysis . Naturally occurring potassium is composed of three isotopes , of which K is radioactive . Traces of K are found in all potassium, and it is the most common radioisotope in the human body. Potassium ions are vital for the functioning of all living cells. The transfer of potassium ions across nerve cell membranes
10807-405: The same effect. Antihydrogen ( H ) is the antimatter counterpart to hydrogen. It consists of an antiproton with a positron . Antihydrogen is the only type of antimatter atom to have been produced as of 2015 . Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass and >90% by number of atoms. Most of
10914-790: The surface of the Canadian province of Saskatchewan . The deposits are located in the Elk Point Group produced in the Middle Devonian . Saskatchewan, where several large mines have operated since the 1960s pioneered the technique of freezing of wet sands (the Blairmore formation) to drive mine shafts through them. The main potash mining company in Saskatchewan until its merge was the Potash Corporation of Saskatchewan , now Nutrien . The water of
11021-517: The tanning of leathers . Major potassium chemicals are potassium hydroxide, potassium carbonate, potassium sulfate, and potassium chloride. Megatons of these compounds are produced annually. KOH is a strong base, which is used in industry to neutralize strong and weak acids , to control pH and to manufacture potassium salts . It is also used to saponify fats and oils , in industrial cleaners, and in hydrolysis reactions, for example of esters . Potassium nitrate ( KNO 3 ) or saltpeter
11128-443: Was first used by Humphry Davy in 1807. Although the electrolysis process was developed and used in industrial scale in the 1920s, the thermal method by reacting sodium with potassium chloride in a chemical equilibrium reaction became the dominant method in the 1950s. The production of sodium potassium alloys is accomplished by changing the reaction time and the amount of sodium used in the reaction. The Griesheimer process employing
11235-403: Was formerly used as a sedative and in photography. While potassium chromate ( K 2 CrO 4 ) is used in the manufacture of a host of different commercial products such as inks , dyes , wood stains (by reacting with the tannic acid in wood), explosives , fireworks , fly paper , and safety matches , as well as in the tanning of leather, all of these uses are due to the chemistry of
11342-433: Was not understood. Georg Ernst Stahl obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, and Henri Louis Duhamel du Monceau was able to prove this difference in 1736. The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus Antoine Lavoisier did not include
11449-521: Was used in the Hindenburg airship, which was destroyed in a midair fire over New Jersey on 6 May 1937. The incident was broadcast live on radio and filmed. Ignition of leaking hydrogen is widely assumed to be the cause, but later investigations pointed to the ignition of the aluminized fabric coating by static electricity . But the damage to hydrogen's reputation as a lifting gas was already done and commercial hydrogen airship travel ceased . Hydrogen
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