Science Fair Project Encyclopedia
|Name, Symbol, Number||Yttrium, Y, 39|
|Chemical series||transition metals|
|Group, Period, Block||3 (IIIB), 5, d|
|Density, Hardness||4472 kg/m3, __|
|Appearance|| Silvery white|
|Atomic weight||88.90585 amu|
|Atomic radius (calc.)||180 (212) pm|
|Covalent radius||162 pm|
|van der Waals radius||no data|
|e- 's per energy level||2, 8, 18, 9, 2|
|Oxidation states (Oxide)||3 (weak base)|
|State of matter||Solid (__)|
|Melting point||1799 K (2779 °F)|
|Boiling point||3609 K (6037 °F)|
|Molar volume||19.88 ×10-6 m3/mol|
|Heat of vaporization||363 kJ/mol|
|Heat of fusion||11.4 kJ/mol|
|Vapor pressure||5.31 Pa at 1799 K|
|Speed of sound||3300 m/s at 293.15 K|
|Electronegativity||1.22 (Pauling scale)|
|Specific heat capacity||300 J/(kg*K)|
|Electrical conductivity||1.66 106/(m·ohm)|
|Thermal conductivity||17.2 W/(m*K)|
|1st ionization potential||600 kJ/mol|
|2nd ionization potential||1180 kJ/mol|
|3rd ionization potential||1980 kJ/mol|
|4th ionization potential||5847 kJ/mol|
|5th ionization potential||7430 kJ/mol|
|6th ionization potential||8970 kJ/mol|
|7th ionization potential||11190 kJ/mol|
|8th ionization potential||12450 kJ/mol|
|9th ionization potential||14110 kJ/mol|
|10th ionization potential||18400 kJ/mol|
|Most Stable Isotopes|
|SI units & STP are used except where noted.|
Yttrium 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 color in color 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 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.
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 expansion characteristics to glass.
Yttrium (Ytterby, a Swedish village near Vaxholm) was discovered by 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 Carl Mosander was able to show that yttira 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 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, and ytterbium and yttrium have all been named after this same town.
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 bastnasite (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.
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.
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