Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is never found in nature as a free element. Its only stable isotope, 89Y, is also its only naturally occurring isotope.Symbol: y
Atomic number: 39
Electron configuration: Kr 4d1 5s2
Melting point: 1,522 °C
Atomic mass: 88.90585 ± 0.00002 u
Discovered: 1794