Atomic number:39
Group numbers:3
Period:5
Electronic configuration:[Kr] 4d1 5s2
Formal oxidation number:+3
Electronegativities:1.22
Atomic radius / pm:177.6
Relative atomic mass:88.90585 ± 0.00002
Yttrium was discovered by Johan Gadolin (FI) in 1794. Named after Ytterby, a village in Sweden. It is a silvery, ductile, fairly reactive metal that is easily combustible, reacts with oxygen in water to release hydrogen. Exposed surfaces form oxide film. Yttrium is found in minerals such as monazite, xenotime and yttria. It is combined with europium to make red phosphors for colour TV's. Yttrium oxide and iron oxide combine to form a crystal garnet used in radar.
Density / g dm-3:4469 (293 K)
Molar volume / cm3mol-1:19.89 (293 K)
Electrical resistivity / μΩcm:57 (20 °C)
Thermal conductivity / W m-1K-1:17.2
Melting point / °C:1522
Boiling point / °C:3345
Heat of fusion / kJ mol-1:17.2
Heat of vaporization / kJ mol-1:367.4
Heat of atomization / kJ mol-1:420.45
First ionization energy / kJ mol-1:599.86
Second ionization energy / kJ mol-1:1180.99
Third ionization energy / kJ mol-1:1979.89
in the atmosphere / ppm:-
in the Earth's crust / ppm:20
in the oceans / ppm:0.0003
Crystal structure:
hexagonal
Unit-cell dimensions / pm:
a=364.74, c=573.06
Space group:
P63/mmc
| 38 Strontium <= |
39 Yttrium
|
=> 40 Zirconium |