2007 Schools Wikipedia Selection. Related subjects: Chemical elements
|Name, Symbol, Number||yttrium, Y, 39|
|Chemical series||transition metals|
|Group, Period, Block||3, 5, d|
|Atomic mass||88.90585 (2) g/mol|
|Electron configuration||[Kr] 4d1 5s2|
|Electrons per shell||2, 8, 18, 9, 2|
|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|
(weakly basic oxide)
|Electronegativity||1.22 (Pauling scale)|
| Ionization energies
|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|
|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)
|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|
|Brinell hardness||589 MPa|
|CAS registry number||7440-65-5|
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.
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.
- Yttrium oxide is also used to make yttrium iron garnets which are very effective microwave filters.
- Yttrium iron, aluminium, and gadolinium garnets (e.g. Y3Fe5O12 and Y3Al5O12) 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. (Y1.2Ba0.8CuO4). 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.
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 (YCl3) with potassium. Yttria (Y2O3) 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.
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.) PO4]) and from bastnäsite (0.2% content, [(Ce, La, etc.)(CO3)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.
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.
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.