Strontium

  • strontium, 38sr
    strontium destilled crystals.jpg
    strontium
    pronunciationm/ (stron-shee-əm, -⁠tee-əm)
    appearancesilvery white metallic; with a pale yellow tint[1]
    standard atomic weight ar, std(sr)87.62(1)[2]
    strontium in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson
    ca

    sr

    ba
    rubidiumstrontiumyttrium
    atomic number (z)38
    groupgroup 2 (alkaline earth metals)
    periodperiod 5
    blocks-block
    element category  alkaline earth metal
    electron configuration[kr] 5s2
    electrons per shell2, 8, 18, 8, 2
    physical properties
    phase at stpsolid
    melting point1050 k ​(777 °c, ​1431 °f)
    boiling point1650 k ​(1377 °c, ​2511 °f)
    density (near r.t.)2.64 g/cm3
    when liquid (at m.p.)2.375 g/cm3
    heat of fusion7.43 kj/mol
    heat of vaporization141 kj/mol
    molar heat capacity26.4 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 796 882 990 1139 1345 1646
    atomic properties
    oxidation states+1,[3] +2 (a strongly basic oxide)
    electronegativitypauling scale: 0.95
    ionization energies
    • 1st: 549.5 kj/mol
    • 2nd: 1064.2 kj/mol
    • 3rd: 4138 kj/mol
    atomic radiusempirical: 215 pm
    covalent radius195±10 pm
    van der waals radius249 pm
    color lines in a spectral range
    spectral lines of strontium
    other properties
    natural occurrenceprimordial
    crystal structureface-centered cubic (fcc)
    face-centered cubic crystal structure for strontium
    thermal expansion22.5 µm/(m·k) (at 25 °c)
    thermal conductivity35.4 w/(m·k)
    electrical resistivity132 nΩ·m (at 20 °c)
    magnetic orderingparamagnetic
    magnetic susceptibility−92.0·10−6 cm3/mol (298 k)[4]
    young's modulus15.7 gpa
    shear modulus6.03 gpa
    poisson ratio0.28
    mohs hardness1.5
    cas number7440-24-6
    history
    namingafter the mineral strontianite, itself named after strontian, scotland
    discoverywilliam cruickshank (1787)
    first isolationhumphry davy (1808)
    main isotopes of strontium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    82sr syn 25.36 d ε 82rb
    83sr syn 1.35 d ε 83rb
    β+ 83rb
    γ
    84sr 0.56% stable
    85sr syn 64.84 d ε 85rb
    γ
    86sr 9.86% stable
    87sr 7.00% stable
    88sr 82.58% stable
    89sr syn 50.52 d ε 89rb
    β 89y
    90sr trace 28.90 y β 90y
    category category: strontium
    | references

    strontium is the chemical element with the symbol sr and atomic number 38. an alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. the metal forms a dark oxide layer when it is exposed to air. strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. it occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these.

    both strontium and strontianite are named after strontian, a village in scotland near which the mineral was discovered in 1790 by adair crawford and william cruickshank; it was identified as a new element the next year from its crimson-red flame test color. strontium was first isolated as a metal in 1808 by humphry davy using the then newly-discovered process of electrolysis. during the 19th century, strontium was mostly used in the production of sugar from sugar beet (see strontian process). at the peak of production of television cathode ray tubes, as much as 75 percent of strontium consumption in the united states was used for the faceplate glass.[5] with the replacement of cathode ray tubes with other display methods, consumption of strontium has dramatically declined.[5]

    while natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is radioactive and is one of the most dangerous components of nuclear fallout, as strontium is absorbed by the body in a similar manner to calcium. natural stable strontium, on the other hand, is not hazardous to health.

  • characteristics
  • history
  • occurrence
  • production
  • applications
  • biological role
  • see also
  • references
  • bibliography
  • external links

Strontium, 38Sr
Strontium destilled crystals.jpg
Strontium
Pronunciationm/ (STRON-shee-əm, -⁠tee-əm)
Appearancesilvery white metallic; with a pale yellow tint[1]
Standard atomic weight Ar, std(Sr)87.62(1)[2]
Strontium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Ca

Sr

Ba
rubidiumstrontiumyttrium
Atomic number (Z)38
Groupgroup 2 (alkaline earth metals)
Periodperiod 5
Blocks-block
Element category  Alkaline earth metal
Electron configuration[Kr] 5s2
Electrons per shell2, 8, 18, 8, 2
Physical properties
Phase at STPsolid
Melting point1050 K ​(777 °C, ​1431 °F)
Boiling point1650 K ​(1377 °C, ​2511 °F)
Density (near r.t.)2.64 g/cm3
when liquid (at m.p.)2.375 g/cm3
Heat of fusion7.43 kJ/mol
Heat of vaporization141 kJ/mol
Molar heat capacity26.4 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 796 882 990 1139 1345 1646
Atomic properties
Oxidation states+1,[3] +2 (a strongly basic oxide)
ElectronegativityPauling scale: 0.95
Ionization energies
  • 1st: 549.5 kJ/mol
  • 2nd: 1064.2 kJ/mol
  • 3rd: 4138 kJ/mol
Atomic radiusempirical: 215 pm
Covalent radius195±10 pm
Van der Waals radius249 pm
Color lines in a spectral range
Spectral lines of strontium
Other properties
Natural occurrenceprimordial
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for strontium
Thermal expansion22.5 µm/(m·K) (at 25 °C)
Thermal conductivity35.4 W/(m·K)
Electrical resistivity132 nΩ·m (at 20 °C)
Magnetic orderingparamagnetic
Magnetic susceptibility−92.0·10−6 cm3/mol (298 K)[4]
Young's modulus15.7 GPa
Shear modulus6.03 GPa
Poisson ratio0.28
Mohs hardness1.5
CAS Number7440-24-6
History
Namingafter the mineral strontianite, itself named after Strontian, Scotland
DiscoveryWilliam Cruickshank (1787)
First isolationHumphry Davy (1808)
Main isotopes of strontium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
82Sr syn 25.36 d ε 82Rb
83Sr syn 1.35 d ε 83Rb
β+ 83Rb
γ
84Sr 0.56% stable
85Sr syn 64.84 d ε 85Rb
γ
86Sr 9.86% stable
87Sr 7.00% stable
88Sr 82.58% stable
89Sr syn 50.52 d ε 89Rb
β 89Y
90Sr trace 28.90 y β 90Y
Category Category: Strontium
| references

Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these.

Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in 1808 by Humphry Davy using the then newly-discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beet (see strontian process). At the peak of production of television cathode ray tubes, as much as 75 percent of strontium consumption in the United States was used for the faceplate glass.[5] With the replacement of cathode ray tubes with other display methods, consumption of strontium has dramatically declined.[5]

While natural strontium (which is mostly the isotope strontium-88) is stable, the synthetic strontium-90 is radioactive and is one of the most dangerous components of nuclear fallout, as strontium is absorbed by the body in a similar manner to calcium. Natural stable strontium, on the other hand, is not hazardous to health.