38 rubidium ← strontium → yttrium Ca ↑ Sr ↓ Ba Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	strontium, Sr, 38
Chemical series	alkaline earth metals
Group, Period, Block	2, 5, s
Appearance	silvery white metallic
Standard atomic weight	87.62(1)  g·mol−1
Electron configuration	[Kr] 5s2
Electrons per shell	2, 8, 18, 8, 2
Physical properties
Phase	solid
Density (near r.t.)	2. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Yttrium (ˈɪtriəm is a Chemical element with symbol Y and Atomic number 39 Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Barium (ˈbɛəriəm is a Chemical element. It has the symbol Ba, and Atomic number 56 This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered A period 5 element is one of the Chemical elements in the fifth row (or period) of the periodic table of the elements. See also Electron configuration The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Krypton (ˈkrɪptən or /ˈkrɪptɒn/ from kryptos "hidden" is a Chemical element with the symbol Kr and Atomic number 36 The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 64  g·cm−3
Liquid density at m.p.	2. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 375  g·cm−3
Melting point	1050 K (777 °C, 1431 °F)
Boiling point	1655 K (1382 °C, 2520 °F)
Heat of fusion	7. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 43  kJ·mol−1
Heat of vaporization	136. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 9  kJ·mol−1
Specific heat capacity	(25 °C) 26. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 4  J·mol−1·K−1
Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k at T(K) 796 882 990 1139 1345 1646
Atomic properties
Crystal structure	cubic face centered
Oxidation states	2, 1,[1] (strongly basic oxide)
Electronegativity	0. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 95 (Pauling scale)
Ionization energies (more)	1st:  549. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively 5  kJ·mol−1
	2nd:  1064. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material 2  kJ·mol−1
	3rd:  4138  kJ·mol−1
Atomic radius	200  pm
Atomic radius (calc. Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth )	219  pm
Covalent radius	192  pm
Miscellaneous
Magnetic ordering	paramagnetic
Electrical resistivity	(20 °C) 132 n Ω·m
Thermal conductivity	(300 K) 35. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 4  W·m−1·K−1
Thermal expansion	(25 °C) 22. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes 5  µm·m−1·K−1
Shear modulus	6. In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear 1  GPa
Poisson ratio	0. Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 28
Mohs hardness	1. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5
CAS registry number	7440-24-6
Selected isotopes
Main article: Isotopes of strontium iso NA half-life DM DE (MeV) DP 82Sr syn 25. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The Alkali earth metal Strontium ( Sr) has four stable naturally occurring Isotopes 84Sr (0 Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 36 d ε - 82Rb 83Sr syn 1. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 35 d ε - 83Rb β+ 1. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Positron emission is a type of Beta decay, sometimes referred to as " beta plus " (&beta+ 23 83Rb γ 0. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 76, 0. 36 - 84Sr 0. 56% 84Sr is stable with 46 neutrons 85Sr syn 64. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 84 d ε - 85Rb γ 0. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 514D - 86Sr 9. Delayed nuclear radiation can occur in a Nuclear decay. It happens when an Isotope decays into a very short-lived isotope and then decays again to a relatively long-lived 86% 86Sr is stable with 48 neutrons 87Sr 7. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 0% 87Sr is stable with 49 neutrons 88Sr 82. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 58% 88Sr is stable with 50 neutrons 89Sr syn 50. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 52 d ε 1. 49 89Rb β- 0. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 909D 89Y 90Sr syn 28. Yttrium (ˈɪtriəm is a Chemical element with symbol Y and Atomic number 39 A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 90 y β- 0. A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun 546 90Y
References

Strontium (pronounced /ˈstrɒntiəm/) is a chemical element with the symbol Sr and the atomic number 38. Yttrium (ˈɪtriəm is a Chemical element with symbol Y and Atomic number 39 Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered The metal turns yellow when exposed to air. It occurs naturally in the minerals celestine and strontianite. Celestine or celestite ( Sr[[Sulfur S]] O 4 is a Mineral consisting of Strontium Sulfate. Strontianite ( Sr[[Carbon C]] O 3 is a Mineral consisting of Strontium carbonate, named after the village of Strontian, The ⁹⁰Sr isotope is present in radioactive fallout and has a half-life of 28. Strontium-90 (90Sr is a Radioactive Isotope of Strontium, with a Half life of 28 Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Fallout is the residual radiation hazard from a Nuclear explosion, so named because it "falls out" of the atmosphere into which it is spread during the explosion Half-Life (computer-game page here It's already listed in the disambiguation page 90 years.

Contents 1 Notable characteristics 2 Applications 3 Compounds 4 History 5 Occurrence 6 Isotopes 7 Precautions 8 Effect on the human body 9 See also 10 References

Notable characteristics

Due to its extreme reactivity to air, this element occurs naturally only in compounds with other elements, as in the minerals strontianite and celestite. Strontianite ( Sr[[Carbon C]] O 3 is a Mineral consisting of Strontium carbonate, named after the village of Strontian, Celestine or celestite ( Sr[[Sulfur S]] O 4 is a Mineral consisting of Strontium Sulfate.

Strontium is a bright silvery metal that is softer than calcium and even more reactive in water, which strontium decomposes on contact with to produce strontium hydroxide and hydrogen gas. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Water is a common Chemical substance that is essential for the survival of all known forms of Life. Strontium hydroxide, Sr(OH2 is a caustic Alkali composed of one Strontium Ion and two Hydroxide ions Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 It burns in air to produce both strontium oxide and strontium nitride, but since it does not react with nitrogen below 380°C it will only form the oxide spontaneously at room temperature. Strontium oxide or strontia, SrO is formed when Strontium reacts with Oxygen. Strontium nitride, Sr3N2 is produced by burning Strontium metal in air (resulting in a mixture with Strontium oxide) or in Nitrogen Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 It should be kept under kerosene to prevent oxidation; freshly exposed strontium metal rapidly turns a yellowish color with the formation of the oxide. Kerosene, sometimes spelled kerosine in scientific and industrial usage is a Combustible Hydrocarbon liquid Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Yellow is the Color evoked by light that stimulates both the L and M (long and medium wavelength Cone cells of the Retina about equally Finely powdered strontium metal will ignite spontaneously in air. Volatile strontium salts impart a crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Crimson is a strong bright deep Red color combined with some Blue, resulting in a tiny degree of Purple. Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. The term "pyrotechnics" can also be used for Fireworks events A flare, also sometimes called a fusee, is a type of Pyrotechnic that produces a brilliant light or intense heat without an Explosion. Natural strontium is a mixture of four stable isotopes. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides

Applications

As a pure metal strontium is being used in strontium 90%-aluminium 10% alloys of an eutectic composition for the modification of aluminium-silicon casting alloys. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has The primary use for strontium compounds is in glass for colour television cathode ray tubes to prevent X-ray emission. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many The cathode ray tube (CRT is a Vacuum tube containing an Electron gun (a source of electrons and a Fluorescent screen with internal or X-radiation (composed of X-rays) is a form of Electromagnetic radiation.

Other uses:

• ⁸⁹Sr is the active ingredient in Metastron, a radiopharmaceutical used for bone pain secondary to metastatic prostate cancer. The Alkali earth metal Strontium ( Sr) has four stable naturally occurring Isotopes 84Sr (0 Radiopharmacology is the study and preparation of radiopharmaceuticals, which are radioactive Pharmaceuticals Radiopharmaceuticals are used in the field Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets, The strontium acts like calcium and is preferentially incorporated into bone at sites of increased osteogenesis. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Osteogenesis is the process of laying down new Bone material by Osteoblasts It occurs in two different ways Either by Intramembranous Osteogenesis (see Intramembranous This localization focuses the radiation exposure on the cancerous lesion.
• ⁹⁰Sr has been used as a power source for radioisotope thermoelectric generators (RTGs). Strontium-90 (90Sr is a Radioactive Isotope of Strontium, with a Half life of 28 A radioisotope thermoelectric generator ( RTG, RITEG) is an Electrical generator which obtains its power from Radioactive decay. ⁹⁰Sr produces about 0. 93 watts of heat per gram (it is lower for the grade of ⁹⁰Sr used in RTGs, which is strontium fluoride). Strontium fluoride, SrF2, also called strontium difluoride and strontium(II fluoride, is a Fluoride of Strontium. ^[2] However, ⁹⁰Sr has a lifetime approximately 3 times shorter and has a lower density than ²³⁸Pu, another RTG fuel. Plutonium 238, is a Radioactive isotope of Plutonium with a half-life of 87 The main advantage of ⁹⁰Sr is that it is cheaper than ²³⁸Pu and is found in nuclear waste. Radioactive wastes are Waste types containing radioactive Chemical elements that do not have a practical purpose
• ⁹⁰Sr is also used in cancer therapy. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Its beta emission and long half-life is ideal for superficial radiotherapy. Radiation therapy (or radiotherapy) is the medical use of Ionizing radiation as part of Cancer treatment to control Malignant
• Strontium is one of the constituents of AJ62 alloy, a durable magnesium alloy used in car and motorcycle engines by BMW. ( BMW) (Bavarian Motor Works is an independent German automobile manufacturer founded in 1916

⁸⁷Sr/⁸⁶Sr ratios are commonly used to determine the likely provenance areas of sediment in natural systems, especially in marine and fluvial environments. Dasch (1969) showed that surface sediments of Atlantic displayed ⁸⁷Sr/⁸⁶Sr ratios that could be regarded as bulk averages of the ⁸⁷Sr/⁸⁶Sr ratios of geological terranes from adjacent landmasses. A good example of a fluvial-marine system to which Sr isotope provenance studies have been successfully employed is the River Nile-Mediterranean system (Krom et al, 1999; Krom et al, 2002; Talbot et al. 2000). Due to the differing ages of the rocks that constitute the majority of the Blue and White Nile catchment areas the changing provenance of sediment reaching the River Nile delta and East Mediterranean Sea can be discerned through Sr isotopic studies. Such changes are climatically controlled in the Late Quaternary.

More recently, ⁸⁷Sr/⁸⁶Sr ratios have also been used to determine the source of ancient archaeological materials such as timbers and corn in Chaco Canyon, New Mexico (English et al, 2001; Benson et al, 2003). ⁸⁷Sr/⁸⁶Sr ratios in teeth may also be used to track animal migrations (Barnett-Johnson, 2007; Porder et al. , 2003) or in criminal forensics.

Strontium atoms are used in an experimental atomic clock with record-setting accuracy. An atomic clock is a type of Clock that uses an Atomic resonance Frequency standard as its timekeeping element ^[3]

Compounds

• Ferrite magnets and refining zinc. Ferrites are a class of Chemical compounds with the formula AB2O4 where A and B represent various metal Cations usually including Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30
• Strontium titanate has an extremely high refractive index and an optical dispersion greater than that of diamond, making it useful in a variety of optics applications. Strontium titanate is an Oxide of Strontium and Titanium with the Chemical formula Sr[[titanium Ti]] O 3 The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium In Optics, dispersion is the phenomenon in which the Phase velocity of a wave depends on its frequency In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in This quality has also led to it being cut into gemstones, in particular as a diamond simulant. A gemstone or gem, also called a precious or semi-precious stone, is a piece of attractive Mineral, which &mdash when cut and polished &mdash This article addresses the many imitations of diamond For a broader discussion of diamonds see Diamond. However, it is very soft and easily scratches so it is rarely used.
• Strontium carbonate, Strontium nitrate, and Strontium sulfate are commonly used in fireworks for red color. Strontium carbonate (SrCO3 is the carbonate salt of strontium that has the appearance of a white or grey powder Strontium nitrate Sr ( N[[Oxygen O3]]2 is an acid salt of Strontium. Strontium sulfate (SrSO4 is the sulfate salt of Strontium. It is a white odorless crystalline powder A firework is classified as a low explosive pyrotechnic device used primarily for aesthetic and entertainment purposes
• Strontium aluminate is used as a bright phosphor with long persistence of phosphorescence. Strontium aluminate ( SRA, SrAl, 24 is a solid odorless nonflammable pale yellow powder heavier than water A phosphor is a substance that exhibits the phenomenon of Phosphorescence (sustained glowing after exposure to energized particles such as Electrons Phosphorescence is a specific type of Photoluminescence related to fluorescence.
• Strontium chloride is sometimes used in toothpastes for sensitive teeth. Strontium chloride (SrCl2 is a Salt of Strontium and Chloride. Toothpaste is a Paste or Gel Dentifrice used to clean and maintain the aesthetics and health of Teeth. One popular brand includes 10% total strontium chloride hexahydrate by weight.
• Strontium oxide is sometimes used to improve the quality of some pottery glazes. Strontium oxide or strontia, SrO is formed when Strontium reacts with Oxygen. Pottery is the Ceramic ware made by potters It also refers to a group of materials that includes Earthenware, Stoneware Glaze is a layer or coating of a Vitreous substance which has been fired to fuse to a ceramic object to color decorate strengthen or waterproof it
• Strontium is also commonly used in aerosol paint, such as the Spanish Montana (Montana Hardcore). This is one of the most likely sources of exposure to the public.
• Strontium ranelate is used in the treatment of osteoporosis. Strontium ranelate, a strontium(II salt of Ranelic acid, is a medication for Osteoporosis marketed as Protelos or Protos It is a prescription drug in the EU and UK, but not in the USA, and is marketed by Servier, a French drug house, as Protelos.
• Strontium citrate is also used in the treatment of osteoporosis and is available over-the-counter from a number of manufacturers.

History

The mineral strontianite is named after the Scottish village of Strontian, having been discovered in the lead mines there in 1787. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Strontianite ( Sr[[Carbon C]] O 3 is a Mineral consisting of Strontium carbonate, named after the village of Strontian, Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Strontian is the main Village in Sunart, an area in western Lochaber, Highland, Scotland, on the A861 road. Year 1787 ( MDCCLXXXVII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common ^[4] Adair Crawford recognized it as differing from other barium minerals in 1790. Adair Crawford FRS (1748 - 1795 a chemist and physician was a pioneer in the development of calorimetric methods for measuring the Specific heat capacity Barium (ˈbɛəriəm is a Chemical element. It has the symbol Ba, and Atomic number 56 Year 1790 ( MDCCXC) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year Strontium itself was discovered in 1798 by Thomas Charles Hope, and metallic strontium was first isolated by Sir Humphry Davy in 1808 using electrolysis. Year 1798 ( MDCCXCVIII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Thomas Charles Hope (21 July 1766 - 13 June 1844 was in 1795 selected by Joseph Black as his assistant and eventual successor to the professorship of Chemistry at the Sir Humphry Davy 1st Baronet FRS MRIA (17 December 1778 &ndash 29 May 1829 was a British Chemist and inventor Year 1808 ( MDCCCVIII) was a Leap year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Leap year In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current

Strontium was among the radioactive materials released by the 1957 Windscale fire. Year 1957 ( MCMLVII) was a Common year starting on Tuesday (link displays the 1957 Gregorian calendar) On October 10, 1957, the Graphite core of a British Nuclear reactor at Windscale, Cumbria, caught fire releasing substantial amounts

Occurrence

In 2005, China was the top producer of strontium with almost two-thirds world share followed by Spain and Mexico, reports the British Geological Survey. The British Geological Survey (BGS is a partly publicly-funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its Continental

Strontium commonly occurs in nature, the 15th most abundant element on earth, averaging 0. 034% of all igneous rock and is found chiefly as the form of the sulfate mineral celestite (SrSO₄) and the carbonate strontianite (SrCO₃). A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Celestine or celestite ( Sr[[Sulfur S]] O 4 is a Mineral consisting of Strontium Sulfate. In Chemistry, a carbonate is a salt or Ester of Carbonic acid. Strontianite ( Sr[[Carbon C]] O 3 is a Mineral consisting of Strontium carbonate, named after the village of Strontian, Of the two, celestite occurs much more frequently in sedimentary deposits of sufficient size to make development of mining facilities attractive. Strontianite would be the more useful of the two common minerals because strontium is used most often in the carbonate form, but few deposits have been discovered that are suitable for development. The metal can be prepared by electrolysis of melted strontium chloride mixed with potassium chloride:

Sr²⁺ + 2 e^- → Sr

2 Cl^- → Cl_{2 (g)} + 2 e^-

Alternatively it is made by reducing strontium oxide with aluminium in a vacuum at a temperature at which strontium distills off. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Strontium chloride (SrCl2 is a Salt of Strontium and Chloride. The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. This page is about the physical properties of gas as a state of matter An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element WikipediaNaming This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture Three allotropes of the metal exist, with transition points at 235 and 540 °C. Allotropy (Gr allos, other and tropos, manner is a behavior exhibited by certain Chemical elements these elements can exist in two or more different In the field of Fluid dynamics the point at which the Boundary layer changes from Laminar to Turbulent is called the transition point. The largest commercially exploited deposits are found in England. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland

See also strontium minerals.

Isotopes

Main article: Isotopes of strontium

The alkali earth metal strontium has four stable, naturally occurring isotopes: ⁸⁴Sr (0. The Alkali earth metal Strontium ( Sr) has four stable naturally occurring Isotopes 84Sr (0 Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides 56%), ⁸⁶Sr (9. 86%), ⁸⁷Sr (7. 0%) and ⁸⁸Sr (82. 58%). Only ⁸⁷Sr is radiogenic; it is produced by decay from the radioactive alkali metal ⁸⁷Rb, which has a half-life of 4. A radiogenic Nuclide is one that is produced by a process of Radioactive decay. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Rubidium (ruːˈbɪdiəm /rəˈbɪdiəm/ is a Chemical element with the symbol Rb and Atomic number 37 Half-Life (computer-game page here It's already listed in the disambiguation page 88 × 10¹⁰ years. Thus, there are two sources of ⁸⁷Sr in any material: that formed during primordial nucleo-synthesis along with ⁸⁴Sr, ⁸⁶Sr and ⁸⁸Sr, as well as that formed by radioactive decay of ⁸⁷Rb. The ratio ⁸⁷Sr/⁸⁶Sr is the parameter typically reported in geologic investigations; ratios in minerals and rocks have values ranging from about 0. Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere 7 to greater than 4. 0. Because strontium has an atomic radius similar to that of calcium, it readily substitutes for Ca in minerals. Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific

Sixteen unstable isotopes are known to exist. Of greatest importance are ⁹⁰Sr with a half-life of 28. Half-Life (computer-game page here It's already listed in the disambiguation page 78 years and ⁸⁹Sr with a half-life of 50. Half-Life (computer-game page here It's already listed in the disambiguation page 5 days.

• ⁹⁰Sr is a by-product of nuclear fission which is found in nuclear fallout and presents a health problem since it substitutes for calcium in bone, preventing expulsion from the body. Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may Fallout is the residual radiation hazard from a Nuclear explosion, so named because it "falls out" of the atmosphere into which it is spread during the explosion Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce This isotope is one of the best long-lived high-energy beta emitters known, and is used in SNAP (Systems for Nuclear Auxiliary Power) devices. Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 A radioisotope thermoelectric generator ( RTG, RITEG) is an Electrical generator which obtains its power from Radioactive decay. These devices hold promise for use in spacecraft, remote weather stations, navigational buoys, etc, where a lightweight, long-lived, nuclear-electric power source is required. A spacecraft is a Vehicle or machine designed for Spaceflight. The 1986 Chernobyl nuclear accident contaminated a vast area with ⁹⁰Sr. The Chernobyl disaster was a nuclear reactor accident in the Chernobyl Nuclear Power Plant in the Soviet Union. ⁹⁰Sr confined inside a concave silver plaque is also used for the medical treatment of a resected pterygium. Pterygium usually refers to a benign growth of the Conjunctiva.
• ⁸⁹Sr is a short-lived artificial radioisotope which provides a health benefit since it substitutes for calcium in bone. Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce In circumstances where cancer patients have widespread and painful bony metastases (secondaries), the administration of ⁸⁹Sr results in the delivery of radioactive emissions (beta particles in this case) directly to the area of bony problem (where calcium turnover is greatest). Metastasis ( Greek: displacement μετά=next + στάσις=placement, plural metastases) sometimes abbreviated mets, Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 The ⁸⁹Sr is manufactured as the chloride salt (which is soluble), and when dissolved in normal saline can be injected intravenously. Typically, cancer patients will be treated with a dose of 150 MBq. The becquerel (symbol Bq) is the SI derived unit of radioactivity. The patient needs to take precautions following this because their urine becomes contaminated with radioactivity, so they need to sit to urinate and double flush the toilet. The beta particles travel about 3. Beta particles are high-energy high-speed Electrons or Positrons emitted by certain types of Radioactive nuclei such as Potassium -40 5mm in bone (energy 0. 583 MeV) and 6. 5mm in tissue, so there is no requirement to isolate patients who have been treated except to say they should not have any one (especially young children) sitting in their laps for 10-40 days. The variation in time results from the variable clearing time for ⁸⁹Sr which depends on renal function and the number of bony metastases. With a lot of bony metastases, the entire ⁸⁹Sr dose can be taken up into bone and so the entire radioactivity is retained to decay over a 50. 5 day half-life. However, where there are few bony metastases, the large proportion of ⁸⁹Sr not taken up by the bone will be filtered by the kidney, so that the effective half-life (a combination of the physical and biological half-life) will be much shorter.

Precautions

In its pure form strontium is extremely reactive with air and spontaneously combusts. It is therefore considered to be a fire hazard.

Effect on the human body

The human body absorbs strontium as if it were calcium. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Due to the elements being sufficiently similar chemically, the stable forms of strontium do not pose a significant health threat, but the radioactive ⁹⁰Sr can lead to various bone disorders and diseases, including bone cancer. Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Bone tumor is an inexact term which can be used for both Benign and Malignant abnormal growths found in bone but is most commonly used for primary Tumors The strontium unit is used in measuring radioactivity from absorbed ⁹⁰Sr. The strontium unit is a unit used to measure the amount of Radioactivity from Strontium -90 a Chemical found in Nuclear fallout, in

An innovative drug made by combining strontium with ranelic acid has aided in bone growth, boosted bone density and lessened vertebral, peripheral and hip fractures. Ranelic acid is an Organic acid capable of chelating metal Cations Strontium ranelate, made by combining strontium(II with Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce A bone fracture (sometimes abbreviated # or Fx or Fx) is a medical condition in which a Bone is cracked or broken ^[5][6] Women receiving the drug showed a 12. 7% increase in bone density. Women receiving a placebo had a 1. 6% decrease. Half the increase in bone density (measured by x-ray densitometry) is attributed to the higher atomic weight of Sr compared with calcium, whereas the other half a true increase in bone mass. It means that strontium ranelate creates new, stronger bone. Strontium ranelate (marketed under the trade names Protelos, Osseor, Protos, Bivalos, Protaxos, Ossum) is registered for treatment of osteoporosis in many countries all over the world. Strontium ranelate has been shown to strengthen bones, according to presentations given at the IOF World Congress on Osteoporosis, in June of 2006. It also reduced bone resorption.

Strontium ranelate is registered as a prescription drug in Europe and many countries worldwide. It needs to be prescribed by a doctor, delivered by a pharmacist, and requires strict medical supervision. Currently, (early 2007) it is not available in Canada or the United States.

Several other salts of strontium such as strontium citrate or strontium carbonate are often presented as natural therapies and sold at a dose that is several hundred times higher than the usual strontium intake. Despite the lack of strontium deficit referenced in the medical literature and the lack of information about possible toxicity of strontium supplementation, such compounds can still be sold in the United States under the Dietary Supplements Health and Education Act of 1994. However, their long-term safety and efficacy have never been evaluated on humans using large-scale medical trials. Such compounds should not be administered to humans before further studies are conducted. But, a recent study conducted the NY College of Dental Sciences using strontium citrate on osteoblasts showed marked improvement on bone-building osteoblasts (http://iadr.confex.com/iadr/2007orleans/techprogram/abstract_89231.htm. Biochemically, it doesn't matter what form of strontium you take as all all forms are must dissolve in the stomach, become ionized and then protein-bound in the intestinal tract to be absorbed. Servier developed strontium renalate simply as a way for them to patent a new strontium compound. In fact, strontium citrate is far more soluble than the strontium renalate and should be less toxic, all this has not been proven.

Strontium compounds have been used successfully since the 1950's to treat osteoporosis with no toxicity. It was only the hysteria created by the strontium-90 fallout and the later introduction of HRT therapy followed by the aldonterates that caused research on strontium to be halted. However, Servier has found that their strontium renalate has less toxicty, and in some cases a higher effectiveness, than many of the aldonterates used today (see Servier. com, Protelos) for their clinical trial results.

Allegedly, an attempt was made in 1968 to poison Alexander Dubček with Sr-90, but it failed. Year 1968 ( MCMLXVIII) was a Leap year starting on Monday (link will display full calendar of the Gregorian calendar. Alexander Dubček (November 27 1921 – November 7 1992 was a Slovak politician and briefly leader of Czechoslovakia (1968-1969 famous for his attempt to reform

It is thought that, contrary to popular belief, Gladiators were mostly vegetarian which ensured a greater intake of strontium leading to stronger bones and therefore more resistance to the otherwise bone-breaking and crushing attacks of other gladiators. ^[7]

See also

• Strontium compounds

References

1. ^ Strontium: strontium(I) fluoride compound data. Bernath. UWaterloo. ca. Retrieved on 2007-12-10. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1041 - Empress Zoe of Byzantium elevates her adoptive son to the throne of the Eastern Roman Empire as Michael V
2. ^ What are the fuels for radioisotope thermoelectric generators?
3. ^ A. D. Ludlow, T. Zelevinsky, G. K. Campbell, S. Blatt, M. M. Boyd, M. H. G. de Miranda, M. J. Martin, S. M. Foreman, J. Ye, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, Y. Le Coq, Z. W. Barber, N. Poli, N. D. Lemke, K. M. Beck, & C. Oates. 2008. Sr lattice clock at 1x10-16 fractional uncertainty by remote optical evaluation with a Ca clock. Science Express. Posted online Feb. 14.
4. ^ Murray, W. H. (1977) The Companion Guide to the West Highlands of Scotland. London. Collins
5. ^ Meunier PJ, Roux C, Seeman E et al. (2004). "effects of strontium ranelate on the risk of vertebral fracture in women with postmenopausal osteoporosis. ". New England Journal of Medicine 350: 459-468. doi:10.1056/NEJMoa022436. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 14749454.  
6. ^ Reginster JY, Seeman E, De Vernejoul MC et al. (2005). "Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: treatment of peripheral osteoporosis (TROPOS) study". J Clin Metab. 90: 2816-2822. PMID 15728210.  
7. ^ Roman Gladiators beat Pharma company to Osteoporosis drug Medicine Magazine

• Los Alamos National Laboratory – Strontium. Medicine Magazine is a UK Consumer magazine focused on health and medical issues Retrieved on August 5, 2005.
• Dasch, J. (1969). Strontium isotopes in weathering profiles, deep-sea sediments, and sedimentary rocks. Geochimica et Cosmochimica Acta, Vol. 33, pp. 1521-1552.
• Krom et al. (1999). The characterisation of Saharan Dusts and Nile particulate matter in surface sediments from the Levantine basin using Sr isotopes. Marine Geology, Vol. 155, pp. 319-330.
• Krom et al. (2002). Nile River sediment fluctuations over the past 7000 yr and their key role in sapropel development. Geology, Vol. 30, pp. 71-74.
• Talbot et al. , (2000). Strontium isotope evidence for late Pleistocene reestablishment of an integrated Nile drainage network. Geology, Vol. 28, pp. 343-346.
• Barnett-Johnson, R. , Grimes, C. B. , Royer C. F. , Donohoe, C. J. (2007) Identifying the contribution of wild and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the ocean fishery using otolith microstructure as natural tags. Canadian Journal of Fisheries and Aquatic Sciences, Vol. 64, pp. 1683-1692.
• Benson, L. , Cordell, L. , Vincent, K. , Taylor, H. , Stein, J. , Farmer, G. , and Kiyoto, F. (2003) Ancient maize from Chacoan great houses: where was it grown?: Proceedings of the National Academy of Sciences, Vol. 22, pp. 13111-13115.
• English, N. B. , Betancourt, J. L. , Dean, J. S. and J. Quade (2001) Strontium Isotopes Reveal Distant Sources of Architectural Timber in Chaco Canyon, New Mexico. Proceedings of the National Academy of Sciences of the United States of America, Vol. 98, pp. 11891-11896
• Porder, S. , Paytan, A. , and E. A. Hadly (2003) Mapping the origin of faunal assemblages using strontium isotopes. Paleobiology, 29: 197 - 204.

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