Yttrium

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MELTING POINT: 1,522°C
BOILING POINT: 3,338°C
DENSITY: 4.469 g/cm ³
MOST COMMON IONS: Y ³⁺

Carl Axel Arrhenius found in 1787 in a quarry near Ytterby, Sweden, a new mineral, which he named ytterbite, and made a summary analysis of it. Further, the Finnish chemist Johan Gadolin isolated in 1794 from this mineral an impure new oxide that he named ytterbia. Friedrich Wöhler partly purified the metal yttrium in 1828, whereas Carl Gustaf Mosander separated the oxides of yttrium, erbium and terbium in 1843 from a mixture of yttria oxide.

Yttrium is trivalent and has an effective ionic radius of 0.900 angstroms. At room temperature the metal structure is hexagonal, close packed, and diamagnetic . The metal yttrium has a silver-metallic luster and is relatively stable in air.

One stable isotope ⁸⁹ Y and thirty-seven unstable isotopes and isomers have been characterized. All four halides of yttrium are known and are commonly prepared by dissolving the oxide in corresponding acids.

Main yttrium minerals are bastnäsite, kainosite, xerosime, and zinnwaldite. It is estimated that the upper continental crust contains yttrium at a concentration of 20.7 milligrams (0.00073 ounces) per kilogram and seawater contains a total amount of 1,569,000,000 kilograms (1,730,000 tons).

The Porifera Melythoea and the tree Carya sp. are considered accumulator organisms. Yttrium accumulates in bone and teeth, a phenomenon that is explained by its ability to bind to phosphorus-containing compounds, and to polysaccharides. Nucleic acids have high affinities for yttrium, which binds to phosphate at a ratio of 1:3. Yttrium has stimulatory effects on some fungi and other lower organisms. It is believed that yttrium binds to the surface of cells, without penetrating the cell membrane.

Chaim T. Horovitz

Bibliography

Horovitz, Chaim T. (1999–2000). Biochemistry of Scandium and Yttrium. Part 1: Physical and Chemical Fundamentals (1999). Part 2: Biochemistry and Applications(2000). New York: Kluwer Academic/Plenum Publishers.

Lide, David R., ed. (2003). The CRC Handbook of Chemistry and Physics, 84th edition. Boca Raton, FL: CRC Press.