Rubidium is the chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity. Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire. Rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. Rubidium has a standard atomic weight of 85.4678. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope Rb, and 28% is slightly radioactive Rb, with a half-life of 49 billion years—more than three times as long as the estimated age of the universe.
Introduction
Rubidium
Rubidium | Introduction
It is the 37th element. It is on number 37 the alkali metal group. 37th position In Group I called the Alkali metals
where is rubidium found on the periodic table
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Rubidium is the chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity. Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire. Rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. Rubidium has a standard atomic weight of 85.4678. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope Rb, and 28% is slightly radioactive Rb, with a half-life of 49 billion years—more than three times as long as the estimated age of the universe.
Rubidium | Introduction
Rubidium was discovered in 1861 by Robert Bunsen and Gustav Kirchhoff, in Heidelberg, Germany, in the mineral lepidolite through flame spectroscopy. Because of the bright red lines in its emission spectrum, they chose a name derived from the Latin word , meaning "deep red". Rubidium is a minor component in lepidolite. Kirchhoff and Bunsen processed 150 kg of a lepidolite containing only 0.24% rubidium monoxide (RbO). Both potassium and rubidium form insoluble salts with chloroplatinic acid, but those salts show a slight difference in solubility in hot water. Therefore, the less soluble rubidium hexachloroplatinate (RbPtCl) could be obtained by fractional crystallization.
Rubidium | History
Rubidium is the twenty-third most abundant element in the Earth's crust, roughly as abundant as zinc and rather more common than copper. It occurs naturally in the minerals leucite, pollucite, carnallite, and zinnwaldite, which contain as much as 1% rubidium oxide. Lepidolite contains between 0.3% and 3.5% rubidium, and is the commercial source of the element. Some potassium minerals and potassium chlorides also contain the element in commercially significant quantities. Seawater contains an average of 125 µg/L of rubidium compared to the much higher value for potassium of 408 mg/L and the much lower value of 0.3 µg/L for caesium.
Rubidium | Occurrence
Rubidium is the first element placed in period 5. It is an alkali metal, the most reactive group in the periodic table, having properties and similarities with both other alkali metals and other period 5 elements. For example, rubidium has 5 electron shells, a property found in all other period 5 elements, whereas its electron configuration's ending is similar to all other alkali metals: s. Rubidium also follows the trend of increasing reactivity as the atomic number increases in the alkali metals, for it is more reactive than potassium, but less so than caesium. In addition, both potassium and rubidium yield almost the same hue when ignited, so researchers must use different methods to differentiate between these two 1st group elements.
Period 5 element | Rubidium
After reduction of the hexachloroplatinate with hydrogen, the process yielded 0.51 grams of rubidium chloride (RbCl) for further studies. Bunsen and Kirchhoff began their first large-scale isolation of caesium and rubidium compounds with of mineral water, which yielded 7.3 grams of caesium chloride and 9.2 grams of rubidium chloride. Rubidium was the second element, shortly after caesium, to be discovered by spectroscopy, just one year after the invention of the spectroscope by Bunsen and Kirchhoff. The two scientists used the rubidium chloride to estimate that the atomic weight of the new element was 85.36 (the currently accepted value is 85.47).
Rubidium | History
Rubidium is very susceptible to oxidation in air, similar to most of the other alkali metals, so it readily transforms into rubidium oxide, a yellow solid with the chemical formula RbO.
Period 5 element | Rubidium
Dirubidium is a molecular substance containing two atoms of rubidium found in rubidium vapour. Dirubidium has two active valence electrons. It is studied both in theory and with experiment. The rubidium trimer has also been observed.
Dirubidium | Introduction
The following table has parameters for RbRb the most common for the natural element.
Dirubidium | Molecular constants for excited states
The fundamental series lines for rubidium appear in the near infrared. The valence electron moves from the 4"d" level as the 3"d" is contained in an inner shell. They were observed by R von Lamb. Relevant energy levels are 4"p"4"d" "j"=5/2 19,355.282 cm and "j"=3/2 19,355.623 cm, and the first "f" levels at 4"p"4"f" "j"=5/2 26,792.185 cm and "j"=7/2 26,792.169 cm.
Fundamental series | Rubidium
The next year, they discovered caesium in the mineral water from Bad Dürkheim, Germany. Their discovery of rubidium came the following year in Heidelberg, Germany, finding it in the mineral lepidolite. The names of rubidium and caesium come from the most prominent lines in their emission spectra: a bright red line for rubidium (from the Latin word "rubidus", meaning dark red or bright red), and a sky-blue line for caesium (derived from the Latin word "caesius", meaning sky-blue). Around 1865 John Newlands produced a series of papers where he listed the elements in order of increasing atomic weight and similar physical and chemical properties that recurred at intervals of eight; he likened such periodicity to the octaves of music, where notes an octave apart have similar musical functions.
Alkali metal | History
At room temperature, rubidium azide has the same structure as potassium hydrogen fluoride; a distorted cesium chloride structure. At 315 °C and 1 atm, rubidium azide will transition to the normal cesium chloride structure. The "II/I" transition temperature of rubidium azide is within 2 °C of its melting point. Rubidium azide has a high pressure structure transition, which occurs at about 4.8 kilobars of pressure at 0 °C. The transition boundary of the "II/III" transition can be defined by the relationship formula_1, where formula_2 is the pressure in kilobars and formula_3 is the temperature in degrees Celsius.
Rubidium azide | Structure
German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy. The name comes from the Latin word , meaning deep red, the color of its emission spectrum. Rubidium's compounds have various chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms. Rubidium is not a known nutrient for any living organisms. However, rubidium ions have the same charge as potassium ions and are actively taken up and treated by animal cells in similar ways.
Rubidium | Introduction
Rubidium azide is an inorganic compound with the formula RbN. It is the rubidium salt of the azide ion (). Like most azides, it is explosive.
Rubidium azide | Introduction
Rubidium oxide is the chemical compound with the formula RbO. Rubidium oxide is highly reactive towards water, and therefore it would not be expected to occur naturally. The rubidium content in minerals is often calculated and quoted in terms of RbO. In reality, the rubidium is typically present as a component of (actually, an impurity in) silicate or aluminosilicate. A major source of rubidium is lepidolite, KLiAl(Al,Si)O(F,OH), wherein Rb sometimes replaces K. RbO is a yellow colored solid. The related species NaO, KO, and CsO are colorless, pale-yellow, and orange, respectively. The alkali metal oxides MO (M = Li, Na, K, Rb) crystallise in the antifluorite structure.
Rubidium oxide | Introduction
They tried to generate elemental rubidium by electrolysis of molten rubidium chloride, but instead of a metal, they obtained a blue homogeneous substance, which "neither under the naked eye nor under the microscope showed the slightest trace of metallic substance". They presumed that it was a subchloride (); however, the product was probably a colloidal mixture of the metal and rubidium chloride. In a second attempt to produce metallic rubidium, Bunsen was able to reduce rubidium by heating charred rubidium tartrate. Although the distilled rubidium was pyrophoric, they were able to determine the density and the melting point. The quality of this research in the 1860s can be appraised by the fact that their determined density differs by less than 0.1 g/cm and the melting point by less than 1 °C from the presently accepted values.
Rubidium | History
Rubidium bromide is the bromide of rubidium. It has a NaCl crystal structure, with a lattice constant of 685 picometres. There are several methods for synthesising rubidium bromide. One involves reacting rubidium hydroxide with hydrobromic acid: Another method is to neutralize rubidium carbonate with hydrobromic acid:
Rubidium bromide | Introduction
In the antifluorite motif the positions of the anions and cations are reversed relative to their positions in CaF, with rubidium ions 8 coordinate (cubic) and oxide ions 4 coordinate (tetrahedral).
Rubidium oxide | Introduction
Its atomic percent abundance is 27.835%, and has a half-life of .
Isotopes of rubidium | Rubidium-87
Rubidium chloride is the chemical compound with the formula RbCl. This alkali metal halide is composed of rubidium and chlorine, and finds diverse uses ranging from electrochemistry to molecular biology.
Rubidium chloride | Introduction
Rubidium is the 18th most abundant element in seawater. Because of its large ionic radius, rubidium is one of the "incompatible elements." During magma crystallization, rubidium is concentrated together with its heavier analogue caesium in the liquid phase and crystallizes last. Therefore, the largest deposits of rubidium and caesium are zone pegmatite ore bodies formed by this enrichment process. Because rubidium substitutes for potassium in the crystallization of magma, the enrichment is far less effective than that of caesium. Zone pegmatite ore bodies containing mineable quantities of caesium as pollucite or the lithium minerals lepidolite are also a source for rubidium as a by-product.
Rubidium | Occurrence
Although rubidium is more abundant in Earth's crust than caesium, the limited applications and the lack of a mineral rich in rubidium limits the production of rubidium compounds to 2 to 4 tonnes per year. Several methods are available for separating potassium, rubidium, and caesium. The fractional crystallization of a rubidium and caesium alum (Cs,Rb)Al(SO)·12HO yields after 30 subsequent steps pure rubidium alum. Two other methods are reported, the chlorostannate process and the ferrocyanide process. For several years in the 1950s and 1960s, a by-product of potassium production called Alkarb was a main source for rubidium. Alkarb contained 21% rubidium, with the rest being potassium and a small amount of caesium.
Rubidium | Production
Rubidium hydride is the hydride of rubidium. It has the formula RbH and is an alkali metal hydride. It is synthesized using rubidium metal to react with hydrogen gas. As a hydride of an alkali metal, it is reactive towards even weak oxidizing agents. A redox reaction will occur with chlorine or fluorine and produce much heat. Rubidium hydride will react violently with water or air and careful storage is necessary.
Rubidium hydride | Introduction
Rubidium is a very soft, ductile, silvery-white metal. It is the second most electropositive of the stable alkali metals and melts at a temperature of . Like other alkali metals, rubidium metal reacts violently with water. As with potassium (which is slightly less reactive) and caesium (which is slightly more reactive), this reaction is usually vigorous enough to ignite the hydrogen gas it produces. Rubidium has also been reported to ignite spontaneously in air. It forms amalgams with mercury and alloys with gold, iron, caesium, sodium, and potassium, but not lithium (even though rubidium and lithium are in the same group).
Rubidium | Characteristics
As a result, Rb is enriched in crustal rocks. The radiogenic daughter, Sr, is produced in this decay process and was produced in rounds of stellar nucleosynthesis predating the creation of the Solar System.
Rubidium–strontium dating | Introduction
Although rubidium is monoisotopic, rubidium in the Earth's crust is composed of two isotopes: the stable Rb (72.2%) and the radioactive Rb (27.8%). Natural rubidium is radioactive, with specific activity of about 670 Bq/g, enough to significantly expose a photographic film in 110 days. Twenty four additional rubidium isotopes have been synthesized with half-lives of less than 3 months; most are highly radioactive and have few uses. Rubidium-87 has a half-life of years, which is more than three times the age of the universe of years, making it a primordial nuclide. It readily substitutes for potassium in minerals, and is therefore fairly widespread.
Rubidium | Isotopes
Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Russian-born scientist of Baltic-German ancestry Karl Ernst Claus discovered the element in 1844 at Kazan State University and named ruthenium in honor of Ruthenia (one of Medieval Latin names for Russia). Ruthenium is usually found as a minor component of platinum ores; the annual production has risen from about 19 tonnes in 2009 to some 35.5 tonnes in 2017.
Ruthenium | Introduction
Rubicline, also referred to as Rb-microcline, is the rubidium analogue of microcline, an important tectosilicate mineral. Its chemical formula is (Rb, K)[AlSiO] with an ideal composition of RbAlSiO. Chemical analysis by electron microprobe indicated the average weight of the crystal is 56.66% SiO, 16.95% AlO, and 23.77% RbO, along with trace amounts of caesium oxide (CsO) and iron(III) oxide (FeO). Rubicline was first discovered in 1998 in Elba, Italy, by a team from the University of Manitoba. It was the first mineral to have been discovered with rubidium as an essential constituent. It has also been found in Mozambique and the Kola Peninsula in Russia.
Rubicline | Introduction
Rutherfordium is a synthetic chemical element with the symbol Rf and atomic number 104, named after New Zealand physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be created in a laboratory. It is radioactive; the most stable known isotope, Rf, has a half-life of approximately 1.3 hours. In the periodic table of the elements, it is a d-block element and the second of the fourth-row transition elements. It is a member of the 7th period and belongs to the group 4 elements. Chemistry experiments have confirmed that rutherfordium behaves as the heavier homologue to hafnium in group 4.
Rutherfordium | Introduction
Rubidium sulfide reacts with sulfur in hydrogen gas to form rubidium pentasulfide, RbS.
Rubidium sulfide | Chemical properties
Rubidium sulfide is an inorganic compound and a salt with the chemical formula RbS. It is a white solid with similar properties to other alkali metal sulfides.
Rubidium sulfide | Introduction
Rubidium iodide is a salt with a melting point of 642 °C. Its chemical formula is RbI. Rubidium iodide can be formed from the reaction of rubidium and iodine:
Rubidium iodide | Introduction
Rubidium forms a number of oxides when exposed to air, including rubidium monoxide (RbO), RbO, and RbO; rubidium in excess oxygen gives the superoxide RbO. Rubidium forms salts with halides, producing rubidium fluoride, rubidium chloride, rubidium bromide, and rubidium iodide.
Rubidium | Compounds
In 1898, when only helium, argon, and krypton were definitively known, Crookes suggested these elements be placed between the hydrogen group and the fluorine group. In 1900, at the Prussian Academy of Sciences, Ramsay and Mendeleev discussed the new inert gases and their location in the periodic table; Ramsay proposed that these elements be put in a new group to the right side of the periodic table, to which Mendeleev agreed. Two weeks before that discussion, Belgian botanist Léo Errera proposed to put those elements in a new group 0, to the Royal Academy of Science, Letters and Fine Arts of Belgium.
History of the periodic table | Changes to the periodic table
In its gas phase, RbCl is diatomic with a bond length estimated at 2.7868 Å. This distance increases to 3.285 Å for cubic RbCl, reflecting the higher coordination number of the ions in the solid phase. Depending on conditions, solid RbCl exists in one of three arrangements or polymorphs as determined with holographic imaging:
Rubidium chloride | Structure
The sodium chloride (NaCl) polymorph is most common. A cubic close-packed arrangement of chloride anions with rubidium cations filling the octahedral holes describes this polymorph. Both ions are six-coordinate in this arrangement. This polymorph's lattice energy is only 3.2 kJ/mol less than the following structure's.
Rubidium chloride | Sodium chloride (octahedral 6:6)
Rubidium fluoride (RbF) is the fluoride salt of rubidium. It is a cubic crystal with rock-salt structure. There are several methods for synthesising rubidium fluoride. One involves reacting rubidium hydroxide with hydrofluoric acid: Another method is to neutralize rubidium carbonate with hydrofluoric acid: Another possible method is to react rubidium hydroxide with ammonium fluoride: The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with halogens:
Rubidium fluoride | Introduction
Rubidium chloride (RbCl) is probably the most used rubidium compound: among several other chlorides, it is used to induce living cells to take up DNA; it is also used as a biomarker, because in nature, it is found only in small quantities in living organisms and when present, replaces potassium. Other common rubidium compounds are the corrosive rubidium hydroxide (RbOH), the starting material for most rubidium-based chemical processes; rubidium carbonate (RbCO), used in some optical glasses, and rubidium copper sulfate, RbSO·CuSO·6HO. Rubidium silver iodide (RbAgI) has the highest room temperature conductivity of any known ionic crystal, a property exploited in thin film batteries and other applications.
Rubidium | Compounds
Rhenium ( meaning: "Rhine") was the second last-discovered of the elements that have a stable isotope (other new elements discovered in nature since then, such as francium, are radioactive). The existence of a yet-undiscovered element at this position in the periodic table had been first predicted by Dmitri Mendeleev. Other calculated information was obtained by Henry Moseley in 1914. In 1908, Japanese chemist Masataka Ogawa announced that he had discovered the 43rd element and named it "nipponium" (Np) after Japan ("Nippon" in Japanese). However, recent analysis indicated the presence of rhenium (element 75), not element 43, although this reinterpretation has been questioned by Eric Scerri.
Rhenium | History
As is the case for rhodium(II), iridium(II) is rarely encountered. One example is iridocene, IrCp. As with rhodocene, iridocene dimerises at room temperature.
Organoiridium compound | Iridium(II)
The elements from actinium to uranium were instead believed to form part of a fourth series of transition metals because of their high oxidation states; accordingly, they were placed in groups 3 through 6. In 1940, neptunium and plutonium were the first transuranic elements to be discovered; they were placed in sequence beneath rhenium and osmium, respectively. However, preliminary investigations of their chemistry suggested a greater similarity to uranium than to lighter transition metals, challenging their placement in the periodic table. During his Manhattan Project research in 1943, American chemist Glenn T. Seaborg experienced unexpected difficulties in isolating the elements americium and curium, as they were believed to be part of a fourth series of transition metals.
History of the periodic table | Actinides
Rubribacterium is an alkaliphilic genus of bacteria from the family of Rhodobacteraceae. "Rubribacterium polymorphum" has been isolated from a Siberian soda lake.
Rubribacterium | Introduction
Rubidium silver iodide is a ternary inorganic compound with the formula RbAgI. Its conductivity involves the movement of silver ions within the crystal lattice. It was discovered while searching for chemicals which had the ionic conductivity properties of alpha-phase silver iodide at temperatures below 146 °C for AgI. RbAgI can be formed by melting together or grinding together stoichiometric quantities of rubidium iodide and silver(I) iodide. The reported conductivity is 25 siemens per metre (that is a 1×1×10 mm bar would have a resistance of 400 ohms along the long axis). The crystal structure is composed of sets of iodine tetrahedra; they share faces through which the silver ions diffuse.
Rubidium silver iodide | Introduction
For several years in the 1950s and 1960s, a by-product of the potassium production called Alkarb was a main source for rubidium. Alkarb contained 21% rubidium while the rest was potassium and a small fraction of caesium. Today the largest producers of caesium, for example the Tanco Mine in Manitoba, Canada, produce rubidium as by-product from pollucite. Today, a common method for separating rubidium from potassium and caesium is the fractional crystallisation of a rubidium and caesium alum (Cs, Rb)Al(SO)·12HO, which yields pure rubidium alum after approximately 30 recrystallisations. The limited applications and the lack of a mineral rich in rubidium limit the production of rubidium compounds to 2 to 4 tonnes per year.
Alkali metal | Production and isolation
Rubidium sulfide has a cubic crystal similar to lithium sulfide, sodium sulfide and potassium sulfide, known as the anti-fluorite structure. Their space groups are formula_3. Rubidium sulfide has a crystal lattice unit cell dimension of a = 765.0 pm.
Rubidium sulfide | Physical properties
Furthermore, we could consider the number of ^{86}_{38}Sr as a constant, for two reasons; firstly this isotope is stable, and secondly the half-time for ^{86}_{37}Rb (whom produced the ^{86}_{38}Sr radiogenic nucleide) is negligible compared to ^{87}_{37}Rb half-time. Hence, \frac{^{87}Sr}{^{86}Sr}= (\frac{^{87}Sr}{^{86}Sr} )_0~+\frac{^{87}Rb}{^{86}Sr}(e^{\lambda t}-1) the isochron equation. After measurements of Rubidum and Strontium concentration in the mineral we can easily determine the age, the t value, of the sample.
Rubidium–strontium dating | Calculating the age
Early in the 20th century, Czech chemist Bohuslav Brauner, and later English physicist Henry Mosely, predicted the existence of an element with atomic weight 61, situated between neodymium and samarium on the periodic table. Various scientists had attempted to isolate the predicted element without success since the time of Mosely's and Brauner's predictions. Working in 1945, Charles D. Coryell, Lawrence E. Glendenin and Jacob A. Marinsky carried out experiments on isolation of the missing element. These experiments were conducted at Clinton Laboratories in Oak Ridge, Tennessee (officially renamed Oak Ridge National Laboratory in 1947). They obtained element 61 by two means, including as a nuclear fission product of uranium and the neutron bombardment of neodymium, all conducted in graphite reactors.
Harold G. Richter | Promethium
Rubidium perchlorate, RbClO, is the perchlorate of rubidium. It is an oxidizing agent, as are all perchlorates.
Rubidium perchlorate | Introduction
The sphalerite polymorph of rubidium chloride has not been observed experimentally. This is consistent with the theory; the lattice energy is predicted to be nearly 40.0 kJ/mol smaller in magnitude than those of the preceding structures.
Rubidium chloride | Sphalerite (tetrahedral 4:4)
The other alkali metals also form dimers: dilithium Li, Na, K, and Cs. The rubidium trimer has also been observed on the surface of helium nanodroplets. The trimer, Rb has the shape of an equilateral triangle, bond length of 5.52 A˚ and a binding energy of 929 cm.
Dirubidium | Related species
From the 1860s through 1871, early forms of the periodic table proposed by Dmitri Mendeleev contained a gap between molybdenum (element 42) and ruthenium (element 44). In 1871, Mendeleev predicted this missing element would occupy the empty place below manganese and have similar chemical properties. Mendeleev gave it the provisional name "ekamanganese" (from "eka"-, the Sanskrit word for "one)" because the predicted element was one place down from the known element manganese.
Technetium | Search for element 43
Many early researchers, both before and after the periodic table was published, were eager to be the first to discover and name the missing element. Its location in the table suggested that it should be easier to find than other undiscovered elements.
Technetium | Early misidentifications
Iridium is a chemical element with symbol Ir and atomic number 77. Iridium may also refer to:
Iridium (disambiguation) | Introduction
Every 18 mg of rubidium chloride is equivalent to approximately one banana equivalent dose due to the large fraction (27.8%) of naturally-occurring radioactive isotope rubidium-87.
Rubidium chloride | Radioactivity
Rutherfordium was reportedly first detected in 1966 at the Joint Institute of Nuclear Research at Dubna (then in the Soviet Union). Researchers there bombarded Pu with accelerated Ne ions and separated the reaction products by gradient thermochromatography after conversion to chlorides by interaction with ZrCl.
Group 4 element | Rutherfordium
Rubidium reacts violently with water and can cause fires. To ensure safety and purity, this metal is usually kept under dry mineral oil or sealed in glass ampoules in an inert atmosphere. Rubidium forms peroxides on exposure even to a small amount of air diffused into the oil, and storage is subject to similar precautions as the storage of metallic potassium. Rubidium, like sodium and potassium, almost always has +1 oxidation state when dissolved in water, even in biological contexts. The human body tends to treat Rb ions as if they were potassium ions, and therefore concentrates rubidium in the body's intracellular fluid (i.e., inside cells).
Rubidium | Precautions and biological effects
Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element in 1844 and named it after Ruthenia, the Latin word for Rus'. Ruthenium usually occurs as a minor component of platinum ores and its annual production is only about 12 tonnes worldwide. Most ruthenium is used for wear-resistant electrical contacts and the production of thick-film resistors. A minor application of ruthenium is its use in some platinum alloys.
Period 5 element | Ruthenium
Dirubidium is produced when rubidium vapour is chilled. The enthalpy of formation (ΔH) in the gas phase is 113.29 kJ/mol. In practice, an oven heated to 600 to 800K with a nozzle can squirt out vapour that condenses into dimers. The proportion of Rb in rubidium vapour varies with its density, which depends on the temperature. At 200° the partial pressure of Rb is only 0.4%, at 400 °C it constitutes 1.6% of the pressure, and at 677 °C the dimer has 7.4% of the vapour pressure (13.8% by mass). The rubidium dimer has been formed on the surface of helium nanodroplets when two rubidium atoms combine to yield the dimer: Rb has also been produced in solid helium matrix under pressure.
Dirubidium | Synthesis and properties
"Z. rubidum" originally occurred in southwestern France, but has spread during the last few decades into central Europe, and has been introduced to U.S. and Canada.
Zodarion rubidum | Distribution
Rubidium hydroxide is the inorganic compound with the formula RbOH. It consists of rubidium cations and one hydroxide anion. It is a colorless solid that is commercially available as aqueous solutions from a few suppliers. Like other strong bases, rubidium hydroxide is highly corrosive. Rubidium hydroxide is formed when rubidium metal is dissolved in water.
Rubidium hydroxide | Introduction
This natural radioactivity became a basis for a mistaken claim of the discovery for element 87 (the next alkali metal after caesium) in 1925. Natural rubidium is similarly slightly radioactive, with 27.83% being the long-lived radioisotope rubidium-87.
Alkali metal | Nuclear
Rubidium has a very low ionization energy of only 406 kJ/mol. Rubidium and potassium show a very similar purple color in the flame test, and distinguishing the two elements requires more sophisticated analysis, such as spectroscopy.
Rubidium | Characteristics
Iridium is found in nature as an uncombined element or in natural alloys; especially the iridium–osmium alloys, osmiridium (osmium-rich), and iridosmium (iridium-rich). In the nickel and copper deposits, the platinum group metals occur as sulfides (i.e. (Pt,Pd)S), tellurides (i.e. PtBiTe), antimonides (PdSb), and arsenides (i.e. ). In all of these compounds, platinum is exchanged by a small amount of iridium and osmium. As with all of the platinum group metals, iridium can be found naturally in alloys with raw nickel or raw copper. A number of iridium-dominant minerals, with iridium as the species-forming element, are known. They are exceedingly rare and often represent the iridium analogues of the above-given ones.
Iridium | Occurrence
The age of a sample is determined by analysing several minerals within multiple subsamples from different parts of the original sample. The Sr/Sr ratio for each subsample is plotted against its Rb/Sr ratio on a graph called an . If these form a straight line then the subsamples are consistent, and the age probably reliable. The slope of the line dictates the age of the sample. Indeed, given the universal law of radioactive decay and the following rubidium beta decay : ^{87}_{37}Rb ->[{\beta -}][{}]~^{87}_{38}Sr ~+e^{-}~+~\bar{\nu_e} we obtain the expression whom describes the growth of Strontium 87 in the rubidium mineral : ^{87}_{38}Sr(t)~=^{87}_{38}Sr(0)~+~^{87}_{37}Rb(e^{\lambda t}-1), \lambda being the decay constant of rubidium.
Rubidium–strontium dating | Calculating the age
The type locality of this iridium anomaly is near Raton, New Mexico. Iridium is a very rare element in the Earth's crust, but is found in anomalously high concentrations (around 100 times greater than normal) in a thin worldwide layer of clay marking the boundary between the Cretaceous and Paleogene periods, 66 million years ago. This boundary is marked by a major extinction event, including that of the dinosaurs along with about 70% of all other species. The clay layer also contains small grains of shocked quartz and, in some places, small weathered glass beads thought to be tektites.
Iridium anomaly | Anomaly characteristics
3,6-Di-O-caffeoylglucose, 1-O-caffeoylxylose and 2,3-O-hexahydroxydiphenoyl-4,6-O-sanguisorboyl-(α/β)-glucose (an ellagitannin constituted with sanguisorbic acid), are found in "R. ulmifolius" subsp. "sanctus".
Rubus ulmifolius subsp. sanctus | Chemistry
Agathidium rubellum is a species of round fungus beetle in the family Leiodidae. It is found in North America.
Agathidium rubellum | Introduction
The ternary hydride is believed to contain both the and the 18-electron anion.
Iridium | Compounds
Further study is suggested to clarify the taxonomy.
Rubus sceleratus | Introduction
It was found that the existing data on rutherfordium-261 was for an isomer, now designated rutherfordium-261m.
Copernicium | Discovery
Rubellimicrobium is a genus of bacteria from the family of Rhodobacteraceae.
Rubellimicrobium | Introduction
Today the largest producers of caesium, such as the Tanco Mine, Manitoba, Canada, produce rubidium as a by-product from pollucite.
Rubidium | Production
At high temperature and pressure, RbCl adopts the caesium chloride (CsCl) structure (NaCl and KCl undergo the same structural change at high pressures). Here, the chloride ions form a simple cubic arrangement with chloride anions occupying the vertices of a cube surrounding a central Rb. This is RbCl's densest packing motif. Because a cube has eight vertices, both ions' coordination numbers equal eight. This is RbCl's highest possible coordination number. Therefore, according to the radius ratio rule, cations in this polymorph will reach their largest apparent radius because the anion-cation distances are greatest.
Rubidium chloride | Caesium chloride (cubic 8:8)
Davyum was the proposed name for a chemical element found by chemist Serge Kern in 1877. It was shown that the material was a mixture of iridium and rhodium. In 1950 it was proposed that the new metal might also have contained rhenium, which had not been discovered in Kern's time.
Davyum | Introduction
The periodic table originally painted in 1904 and discovered during the renovation of the Chemical Auditorium reflects the knowledge of chemistry in the early 20th century.
Gdańsk University of Technology | Periodic Table
Strontium and trace amounts of rubidium, barium and niobium are present in the structure of faizievite. One of the sodium sites is partially vacant, and fluorine may be substituted by oxygen.
Faizievite | Notes on chemistry and structure
The values for barium and radium are almost exactly the same as those of the heavier alkali metals potassium, rubidium, and caesium.
Radium | Chemistry
Rubidium hydrogen sulfate is the rubidium salt of sulfuric acid. It has the formula RbHSO.
Rubidium hydrogen sulfate | Introduction
Iridium fluoride may refer to any of the following:
Iridium fluoride | Introduction
Like other groups, the members of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior: Most of the chemistry has been observed only for the first three members of the group. The chemistry of rutherfordium is not very established and therefore the rest of the section deals only with titanium, zirconium, and hafnium. All the elements of the group are reactive metals with a high melting point (1668 °C, 1854 °C, 2233 °C, 2100 °C?). The reactivity is not always obvious due to the rapid formation of a stable oxide layer, which prevents further reactions.
Group 4 element | Chemistry
Rubidium nitrate is an inorganic compound with the formula RbNO. This alkali metal nitrate salt is white and highly soluble in water.
Rubidium nitrate | Introduction
This was in part a consequence of their similar chemistry and imprecise determination of their atomic masses. Combined with the lack of a known group of similar elements, this rendered the placement of the lanthanides in the periodic table difficult. This discovery led to a restructuring of the table and the first appearance of the 32-column form.
History of the periodic table | Changes to the periodic table
Relativistic stabilization of the 8p subshell should result in a ground-state 8s8p valence electron configuration for element 121, in contrast to the ds configurations of lanthanum and actinium; nevertheless, this anomalous configuration does not appear to affect its calculated chemistry, which remains similar to that of actinium. Its first ionization energy is predicted to be 429.4 kJ/mol, which would be lower than those of all known elements except for the alkali metals potassium, rubidium, caesium, and francium: this value is even lower than that of the period 8 alkali metal ununennium (463 kJ/mol). Similarly, the next superactinide, unbibium (element 122), may be similar to cerium and thorium, with a main oxidation state of +4, but would have a ground-state 7d8s8p valence electron configuration, unlike thorium's 6d7s configuration.
Extended periodic table | Superactinides
He is also known for his studies involving the atomic weight of rubidium.
Jules Piccard | Introduction
He named it scandium, from the Latin "Scandia" meaning "Scandinavia". Chemical experiments on the element proved that Mendeleev's suggestions were correct; along with discovery and characterization of gallium and germanium this proved the correctness of the whole periodic table and periodic law. Nilson was apparently unaware of Mendeleev's prediction, but Per Teodor Cleve recognized the correspondence and notified Mendeleev. Metallic scandium was produced for the first time in 1937 by electrolysis of a eutectic mixture, at 700–800 °C, of potassium, lithium, and scandium chlorides. In 1751, the Swedish mineralogist Axel Fredrik Cronstedt discovered a heavy mineral from the mine at Bastnäs, later named cerite.
Group 3 element | History
Pekka Pyykkö and Burkhard Fricke used computer modeling to calculate the positions of elements up to "Z" = 172, and found that several were displaced from the Madelung rule. As a result of uncertainty and variability in predictions of chemical and physical properties of elements beyond 120, there is currently no consensus on their placement in the extended periodic table.
Extended periodic table | Introduction
Rubidium chloride reacts with sulfuric acid to rubidium hydrogen sulfate.
Rubidium chloride | Reactions
They named element 75 rhenium (Latin "Rhenus" meaning "Rhine"). Rhenium was the last element to be discovered having a stable isotope. The existence of a yet undiscovered element at this position in the periodic table had been predicted by Henry Moseley in 1914. In 1925 they reported that they detected the element in platinum ore and in the mineral columbite. They also found rhenium in gadolinite and molybdenite. In 1928 they were able to extract 1 g of the element by processing 660 kg of molybdenite.
Walter Noddack | Rhenium
Chromium is the fourth transition metal found on the periodic table, and has an electron configuration of [Ar] 3d 4s. It is also the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. This occurs again later in the periodic table with other elements and their electron configurations, such as copper, niobium, and molybdenum. This occurs because electrons in the same orbital repel each other due to their like charges. In the previous elements, the energetic cost of promoting an electron to the next higher energy level is too great to compensate for that released by lessening inter-electronic repulsion.
Chromium | Atomic
The rubidium-strontium dating method is a radiometric dating technique used by scientists to determine the age of rocks and minerals from the quantities they contain of specific isotopes of rubidium (Rb) and strontium (Sr, Sr). Development of this process was aided by German chemists Otto Hahn and Fritz Strassmann, who later went on to discover nuclear fission in December 1938. The utility of the rubidium–strontium isotope system results from the fact that Rb (one of two naturally occurring isotopes of rubidium) decays to Sr with a half-life of 49.23 billion years. In addition, Rb is a highly incompatible element that, during partial melting of the mantle, prefers to join the magmatic melt rather than remain in mantle minerals.
Rubidium–strontium dating | Introduction
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an "estimated" average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. The free element has the third-highest melting point and highest boiling point of any element. Rhenium resembles manganese chemically and is obtained as a by-product of molybdenum and copper ore's extraction and refinement. Rhenium shows in its compounds a wide variety of oxidation states ranging from −1 to +7. Discovered in 1925, rhenium was the last stable element to be discovered.
Period 6 element | Rhenium
As with all azides, it will decompose and release nitrogen gas when heated or severely shocked:
Rubidium azide | Reactions
Among the undiscovered elements, predictions are only available for ununennium and unbinilium (eka-francium and eka-radium), which are predicted to crystallise in body-centered cubic structures like their lighter congeners.
Periodic table (crystal structure) | Table
It has been argued that this is not a valid concern given other periodic table anomalies—thorium, for example, has no f-electrons yet is part of the f-block. As for lawrencium, its gas phase atomic electron configuration was confirmed in 2015 as [Rn]5f7s7p. Such a configuration represents another periodic table anomaly, regardless of whether lawrencium is located in the f-block or the d-block, as the only potentially applicable p-block position has been reserved for nihonium with its predicted configuration of [Rn]5f6d7s7p. Chemically, scandium, yttrium and lutetium (and presumably lawrencium) behave like trivalent versions of the group 1–2 metals. On the other hand, trends going down the group for properties such as melting point, electronegativity and ionic radius, are similar to those found among their group 4–8 counterparts.
Periodic table | Lutetium and lawrencium
Rhipidarctia rubrovitta is a moth in the family Erebidae. It was described by Per Olof Christopher Aurivillius in 1904 and is found in Angola, Cameroon and the Democratic Republic of the Congo.
Rhipidarctia rubrovitta | Introduction
Rubidium perchlorate can be obtained through the careful heating of a rubidium chlorate solution, leading to a disproportionation reaction with the release of oxygen gas: When heated, it decomposes into the chloride and oxygen: It has two polymorphs. Below 279 °C, it crystallizes in orthorhombic crystal system with lattice constants "a" = 0.927 nm, "b" = 0.581 nm, "c" = 0.753 nm. Over 279 °C, it has a cubic structure with lattice constant "a" = 0.770 nm.
Rubidium perchlorate | Preparation and properties
Rubidium sulfate is a sulfate of rubidium. The molecular formula of the compound is RbSO. The molecular weight of this compound is 266.999 g/mol. An acid sulfate of rubidium (rubidium hydrogen sulfate) can be formed. It is soluble in water and is an aqueous solution.
Rubidium sulfate | Introduction
Rubiteucris is a genus of plants in the family Lamiaceae, first described in 1929. It is native to southern China, the Himalayas, and Myanmar.
Rubiteucris | Introduction
In the 1990s, Ken Czerwinski at University of California, Berkeley observed similarities between rutherfordium and plutonium and dubnium and protactinium, rather than a clear continuation of periodicity in groups 4 and 5. More recent experiments on copernicium and flerovium have yielded inconsistent results, some of which suggest that these elements behave more like the noble gas radon rather than mercury and lead, their respective congeners. As such, the chemistry of many superheavy elements has yet to be well-characterized, and it remains unclear whether the periodic law can still be used to extrapolate the properties of undiscovered elements.
History of the periodic table | Relativistic effects and expansions beyond period 7
The examples are irarsite and cuproiridsite, to mention some. Within Earth's crust, iridium is found at highest concentrations in three types of geologic structure: igneous deposits (crustal intrusions from below), impact craters, and deposits reworked from one of the former structures. The largest known primary reserves are in the Bushveld igneous complex in South Africa, (near the largest known impact crater, the Vredefort crater) though the large copper–nickel deposits near Norilsk in Russia, and the Sudbury Basin (also an impact crater) in Canada are also significant sources of iridium. Smaller reserves are found in the United States. Iridium is also found in secondary deposits, combined with platinum and other platinum group metals in alluvial deposits.
Iridium | Occurrence
Work performed from 1964 to 2013 at four laboratories – the Lawrence Berkeley National Laboratory in the US, the Joint Institute for Nuclear Research in the USSR (later Russia), the GSI Helmholtz Centre for Heavy Ion Research in Germany, and RIKEN in Japan – identified and confirmed the elements from rutherfordium to oganesson according to the criteria of the IUPAC–IUPAP Transfermium Working Groups and subsequent Joint Working Parties. These discoveries complete the seventh row of the periodic table. The remaining two transactinides, ununennium (element 119) and unbinilium (element 120), have not yet been synthesized. They would begin an eighth period.
Superheavy element | Discoveries