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Yttrium

2007 Schools Wikipedia Selection. Related subjects: Chemical elements


                39             strontium ← yttrium → zirconium
                Sc
                ↑
                Y
                ↓
                Lu

                                  Periodic Table - Extended Periodic Table

                                                                   General
                                       Name, Symbol, Number yttrium, Y, 39
                                         Chemical series transition metals
                                              Group, Period, Block 3, 5, d
                                                  Appearance silvery white
                                            Atomic mass 88.90585 (2) g/mol
                                     Electron configuration [Kr] 4d^1 5s^2
                                        Electrons per shell 2, 8, 18, 9, 2
                                                       Physical properties
                                                               Phase solid
                                      Density (near r.t.) 4.472 g·cm^−3
                                    Liquid density at m.p. 4.24 g·cm^−3
                                                     Melting point 1799  K
                                                    (1526 ° C, 2779 ° F)
                                                      Boiling point 3609 K
                                                    (3336 ° C, 6037 ° F)
                                         Heat of fusion 11.42 kJ·mol^−1
                                     Heat of vaporization 365 kJ·mol^−1
                          Heat capacity (25 °C) 26.53 J·mol^−1·K^−1

   CAPTION: Vapor pressure

                               P/Pa   1    10   100    1 k    10 k  100 k
                              at T/K 1883 2075 (2320) (2627) (3036) (3607)

                                                         Atomic properties
                                               Crystal structure hexagonal
                                                        Oxidation states 3
                                                      (weakly basic oxide)
                                    Electronegativity 1.22 (Pauling scale)
                                                       Ionization energies
                                             ( more) 1st: 600 kJ·mol^−1
                                                    2nd: 1180 kJ·mol^−1
                                                    3rd: 1980 kJ·mol^−1
                                                      Atomic radius 180 pm
                                              Atomic radius (calc.) 212 pm
                                                    Covalent radius 162 pm
                                                             Miscellaneous
                                                 Magnetic ordering no data
                      Electrical resistivity ( r.t.) (α, poly) 596 nΩ·m
                       Thermal conductivity (300 K) 17.2 W·m^−1·K^−1
                                      Thermal expansion ( r.t.) (α, poly)
                                                           10.6 µm/(m·K)
                               Speed of sound (thin rod) (20 °C) 3300 m/s
                                                  Young's modulus 63.5 GPa
                                                    Shear modulus 25.6 GPa
                                                     Bulk modulus 41.2 GPa
                                                       Poisson ratio 0.243
                                                  Brinell hardness 589 MPa
                                             CAS registry number 7440-65-5
                                                         Selected isotopes

                 CAPTION: Main article: Isotopes of yttrium

                                iso   NA  half-life DM   DE ( MeV)    DP
                                ^87Y syn  3.35 d    ε   -            ^87Sr
                                                    γ   0.48, 0.38 D -
                                ^88Y syn  106.6 d   ε   -            ^88Sr
                                                    γ   1.83, 0.89   -
                                ^89Y 100% Y is stable with 50 neutrons
                                ^90Y syn  2.67 d    β^- 2.28         ^90Zr
                                                    γ   2.18         -
                                ^91Y syn  58.5 d    β^- 1.54         ^91Zr
                                                    γ   1.20         -

                                                                References

   Yttrium ( IPA: /ɪˈtriəm/), is a chemical element in the periodic table
   that has the symbol Y and atomic number 39. A silvery metallic
   transition metal, yttrium is common in rare-earth minerals and two of
   its compounds are used to make the red colour phosphors in cathode ray
   tube displays, such as those used for televisions.

Notable Characteristics

   Yttrium is a silver-metallic, lustrous rare earth metal that is
   relatively stable in air and chemically resembles the lanthanides.
   Shavings or turnings of the metal can ignite in air when they exceed
   400 ° C. When yttrium is finely divided it is very unstable in air. The
   metal has a low neutron cross-section for nuclear capture. The common
   oxidation state of yttrium is +3.

Applications

   Yttrium(III) oxide is the most important yttrium compound and is widely
   used to make YVO[4]:Eu and Y[2]O[3]:Eu phosphors that give the red
   colour in colour television picture tubes. Other uses;
     * Yttrium oxide is also used to make yttrium iron garnets which are
       very effective microwave filters.
     * Yttrium iron, aluminium, and gadolinium garnets (e.g.
       Y[3]Fe[5]O[12]and Y[3]Al[5]O[12]) have interesting magnetic
       properties. Yttrium iron garnet is very efficient as an acoustic
       energy transmitter and transducer. Yttrium aluminium garnet has a
       hardness of 8.5 and is also used as a gemstone (simulated diamond).
     * Small amounts of the element (0.1 to 0.2%) have been used to reduce
       grain size of chromium, molybdenum, titanium, and zirconium. It is
       also used to increase the strength of aluminium and magnesium
       alloys.
     * Used as a catalyst for ethylene polymerization.
     * Yttrium aluminium garnet, yttrium lithium fluoride, and yttrium
       vanadate are used in combination with dopants such as neodymium or
       erbium in infrared lasers.
     * This metal can be used to deoxidize vanadium and other nonferrous
       metals.
     * Yttrium is also used in the manufacture of gas mantles for propane
       lanterns, as a replacement for thorium, which is slightly
       radioactive.
     * Cerium- doped yttrium aluminium garnet (YAG:Ce) crystals are used
       as phosphors to make white LEDs.
     * Yttrium was used as a "secret" element in a superconductor
       developed at the University of Houston, YBaCuO. This superconductor
       operated above 90K, an amazing feat because it can operate at above
       liquid nitrogen's boiling point. (Y[1.2]Ba[0.8]CuO[4]). The matter
       created was a multi-crystal multi-phase mineral, of which were
       black and green.

   Yttrium has been studied for possible use as a nodulizer in the making
   of nodular cast iron which has increased ductility (the graphite forms
   compact nodules instead of flakes to form nodular cast iron).
   Potentially, yttrium can be used in ceramic and glass formulas, since
   yttrium oxide has a high melting point and imparts shock resistance and
   low thermal expansion characteristics to glass.

History

   Yttrium (named for Ytterby, a Swedish village near Vaxholm) was
   discovered by Finnish chemist, physicist and mineralogist Johan Gadolin
   in 1794 and isolated by Friedrich Wohler in 1828 as an impure extract
   of yttria through the reduction of yttrium anhydrous chloride (YCl[3])
   with potassium. Yttria (Y[2]O[3]) is the oxide of yttrium and was
   discovered by Johan Gadolin in 1794 in a gadolinite mineral from
   Ytterby.

   In 1843, the great Swedish chemist Carl Mosander was able to show that
   yttria could be divided into the oxides (or earths) of three different
   elements. "Yttria" was the name used for the most basic one and the
   others were re-named erbia and terbia.

   A quarry is located near the village of Ytterby that yielded many
   unusual minerals that contained rare earths and other elements. The
   elements erbium, terbium, ytterbium, and yttrium have all been named
   after this same small village.

Occurrence

   This element is found in almost all rare-earth minerals and in uranium
   ores but is never found in nature as a free element. Yttrium is
   commercially recovered from monazite sand (3% content, [(Ce, La, etc.)
   PO[4]]) and from bastnäsite (0.2% content, [(Ce, La, etc.)(CO[3])F]).
   It is commercially produced by reducing yttrium fluoride with calcium
   metal but it can also be produced using other techniques. It is
   difficult to separate from other rare earths and when extracted, is a
   dark gray powder.

   Lunar Rock samples from the Apollo program have a relatively high
   yttrium content.

Isotopes

   Natural yttrium is composed of only one isotope (Y-89). The most stable
   radioisotopes are Y-88 which has a half life of 106.65 days and Y-91
   with a half life of 58.51 days. All the other isotopes have half lifes
   of less than a day except Y-87 which has a half life of 79.8 hours. The
   dominant decay mode below the stable Y-89 is electron capture and the
   dominant mode after it is beta emission. Twenty six unstable isotopes
   have been characterized.

   Y-90 exists in equilibrium with its parent isotope strontium-90, which
   is a product of nuclear explosions.

Precautions

   Compounds that contain this element are rarely encountered by most
   people but should be considered to be highly toxic even though many
   compounds pose little risk. Yttrium salts may be carcinogenic. This
   element is not normally found in human tissue and plays no known
   biological role.

   Retrieved from " http://en.wikipedia.org/wiki/Yttrium"
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   with only minor checks and changes (see www.wikipedia.org for details
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