Yttrium

Yttrium,  ₃₉Y

General properties
Name, symbol	Yttrium, Y
Appearance	Silvery-white
Yttrium in the periodic table
Sc ↑ Y ↓ La Strontium ← Yttrium → Zirconium
Atomic number	39
Standard atomic weight (Ar)	88.90584(2)
Group, block	, d-block
Period	period 5
Electron configuration	[Kr] 4d1 5s2
per shell	2, 8, 18, 9, 2
Physical properties
Silvery-white
Phase	Solid
Melting point	1799 K ​(1526 °C, ​2779 °F)
Boiling point	3203 K ​(2930 °C, ​5306 °F)
Density near r.t.	4.472 g/cm3
when liquid, at	4.24 g/cm3
Heat of fusion	11.42 kJ/mol
Heat of	363 kJ/mol
Molar heat capacity	26.53 J/(mol·K)
pressure
Atomic properties
Oxidation states	3, 2, 1 ​(a weakly basic oxide)
Electronegativity	Pauling scale: 1.22
energies	1st: 600 kJ/mol 2nd: 1180 kJ/mol 3rd: 1980 kJ/mol
Atomic radius	empirical: 180 pm
Covalent radius	190±7 pm
Miscellanea
Crystal structure	​Hexagonal close-packed (hcp)
Speed of sound thin rod	3300 m/s (at 20 °C)
Thermal expansion	10.6 µm/(m·K) (α, poly)
Thermal conductivity	17.2 W/(m·K)
Electrical resistivity	5.96·10-7 Ω·m (α, poly)
Magnetic ordering	Paramagnetic
Young's modulus	63.5 GPa
Shear modulus	25.6 GPa
Bulk modulus	41.2 GPa
Poisson ratio	0.243
Brinell hardness	200–589 MPa
CAS Registry Number	7440-65-5
History
Naming	After Ytterby (Sweden) and its mineral ytterbite (gadolinite)
Discovery	Johan Gadolin (1794)
First isolation	Carl Gustav Mosander (1842)

Yttrium is a transition metal with the symbol Y and the atomic number 39. It is chemically similar to the lanthanides, and is often grouped with them, as well as scandium, as a rare earth metal. Yttrium is a powerful reducing agent, but is not a necessary addition to the amateur chemistry lab when cheaper agents, such as magnesium, are readily available.

Properties

Physical

Yttrium is a silvery metal that is not very dense (comparable to titanium). It tends to form crystals which are hexagonally close-packed.

Chemical

Yttrium is a typical rare-earth metal, with similar chemistry to aluminium. It does not corrode in air, yet it has the highest thermodynamic affinity for oxygen of any element. Finely divided yttrium is prone to ignition. In solution, yttrium compounds do not exhibit any color due to the lack of free d or f electrons. Its standard reduction potential is almost exactly the same as that of magnesium. It reacts with acids to form salts, most of which are soluble except for yttrium fluoride and yttrium oxalate. Yttrium sulfate is only slightly soluble. The metal reacts with the halogens to produce trihalides.

Its primary oxidation state is +3. Yttrium(II) compounds exist, but are not accessible to the amateur.

Availability

Yttrium is more common than tin on Earth, but it is very hard to find and expensive (though relatively cheap for a rare-earth element). One source for yttrium, as well as other rare earth metals, is Metallium. It is sold in 5 gram and 50 gram sizes, as well as rods, ampoules, 100 gram ingots, and coins. Yttrium and its compounds occasionally sold on eBay as well.

Projects

• Yttrium thermite?
• Alloys with aluminium?

Handling

Safety

Toxicity

Toxicity data of yttrium compounds is scarce, but they appear to be of low to moderate danger. Yttrium plays no biological role, but acts similarly to calcium within the body. Some yttrium compounds, notably the halides, will hydrolyze when heated and will give off acidic vapors.

Flammability

Small pieces of yttrium metal or powder are flammable. Class D fire extinguishers should be readily available when working with yttrium near an open flame. Water should never be used to extinguish burning yttrium, as it will aggravate the flame.

Storage

Yttrium should be stored away from any corrosive reagents and flame source.

Disposal

Due to its rarity and price, it's best to try to recycle it.

References

Relevant Sciencemadness threads

• Yttrium metal