Yttrium (Y)

Stable Isotopes of Yttrium

Isotope Z(p) N(n) Atomic Mass Natural Abundance Nuclear Spin
Y-89  39  50  88.905849 100.00%  1/2- 


Yttrium was discovered in 1794 by Johann Gadolin. It is named after Ytterby, a village near Vaxholm in Sweden.

A grayish, lustrous metal, yttrium is known only in its tri-positive state. It has a hexagonal close-packed crystal structure that converts to a body-centered cubic structure at 1490 ºC. It is soluble in dilute acids and potassium hydroxide solution, and it decomposes in water.

The chemical properties of yttrium are more similar to those of rare earths than to those of scandium. Yttrium combines with oxygen, forming its only oxide, Y2O3, the reaction of which is much faster at high temperatures, particularly above 400 ºC. The metal, in the form of sponge or small particles, can ignite at this temperature. At ambient temperatures, the metal is slightly tarnished by oxygen or air, forming a very thin film of oxide that protects the metal from further oxidation. The metal reacts with halogens above 200 ºC, forming its trihalides. It combines with nitrogen above 1000 ºC, producing a nitride, YN. It combines at elevated temperatures, forming binary compounds with most nonmetals and some metalloid elements, such as hydrogen, sulfur, carbon, phosphorus, silicon and selenium.

Yttrium alloys have many applications. The metal, doped with rare earths such as europium, is used as a phosphor for color-television receivers. When added to iron, chromium, vanadium, niobium or other metals, it enhances the resistance of these metals and their alloys to high-temperature oxidation and recrystallization. It is a deoxidizer for vanadium and other nonferrous metals. Yttrium-aluminum garnets are used in lasers and in jewelry gemstones. Yttrium-iron garnets are used as transmitters and as transducers of acoustic energy.

Properties of Yttrium

Name Yttrium 
Atomic number 39 
Atomic weight 88.906 
Standard state Solid at 298 °K 
CAS Registry ID 7440-65-5 
Group in periodic table
Group name None 
Period in periodic table
Block in periodic table d-block 
Color Silvery white 
Classification Metallic 
Melting point 1526 °C
Boiling point 3338 °C
Vaporization point 3336 °C
Thermal conductivity 17.2 W/(m·K) at 298.2 °K
Electrical resistivity 59.6 µΩ·cm at 25 °C 
Electronegativity 1.3 
Specific heat 0.3 kJ/kg K
Heat of vaporization 380 kJ·mol-1
Heat of fusion 11.4 kJ·mol-1
Density of liquid 4.24 g/cm3 at 1526 °C 
Density of solid 4.47 g/cm
Electron configuration [Kr]4d15s2 
Atomic radius 1.80 Å 
Oxidation state  +3