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yttrium (Y)

Yttrium ingots. Image copyright:
A silvery-white rare-earth element of group III of the periodic table; it is used in alloys and as a "getter" to help evacuate electron tubes. First isolated in 1828, yttrium is found in monzate sand, bastnaesite, and gadolinite; it was also found in lunar rock samples collected by the Apollo 11 mission.

A red phosphor (yttrium oxide or vanadate excited by europium) is used in color televisions, and yttrium-iron garnets are used in radar.

The commonest isotope of yttrium is 89Y (100%). Yttrium-90 is an artificial radioactive isotope used in radiotherapy.

atomic number 39
relative atomic mass 88.906
relative density 4.47
melting point 1,523°C (2,773°F)
boiling point 3,337°C (6,039°F)

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