|
General |
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 Properties |
Atomic weight | 88.90585 amu |
Atomic radius (calc.) | 180 (212) pm |
Covalent radius | 162 pm |
van der Waals radius | no data |
Electron configuration | [Kr]4d15s2 |
e- 's per energy level | 2, 8, 18, 9, 2 |
Oxidation states (Oxide) | 3 (weak base) |
Crystal structure | Hexagonal |
Physical Properties |
State of matter | Solid (__) |
Melting point | 1799 K (2779 °F) |
Boiling point | 3609 K (6037 °F) |
Molar volume | 19.88 ×10-3 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 |
Miscellaneous |
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 the most important yttrium compound and is widely used to make Y
VO4 europium and Y
2O
3 europium phosphors that give the red color in
color television picture tubes. Other uses;
- Yttrium oxide is also used to make yttrium-iron-garnets which are very effective microwave filters.
- Yttrium iron, aluminum, 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 aluminum 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 aluminum and magnesium alloys.
- Used as a catalyst for ethylene polymerization in laser systems.
- This metal can be used to deoxidize vanadium and other nonferrous metals.
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
Vauxholm[?]) was discovered by
Friedrich Wohler[?] in
1928 as an impure extract of
yttria[?] through the reduction of yttrium anhydrous
chloride (Y
Cl3) with
potassium. Yttria (Y
2O
3) is the oxide of yttruim 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.)(
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.
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
cancerous. This element is not normally found in human tissue and plays no known biological role.