Terbium has the silver-gray luster typical of many metals. It is quite soft, however, and can be cut with a knife. It is also malleable and ductile, meaning it can be hammered into thin sheets and drawn into wires rather easily. The melting point of terbium is 1,356°C (2,473°F) and its boiling point is about 2,800°C (5,000°F). It has a density of 8.332 grams per cubic centimeter.
Like many of its rare earth cousins, terbium is not very active. It does not react with oxygen in the air very easily. It does react with water slowly, however, and will dissolve in acids. Terbium is one of the rarest of the Lanthanides. It ranks about 55th among the elements in the Earth's crust. Continue reading from Chemistry Explained
Terbium was first isolated in 1843 by the Swedish chemist Carl Mosander at Stockholm. He had already investigated cerium oxide and separated a new element from it, lanthanum, and now he focussed his attention on yttrium, discovered in 1794, because he thought this too might harbour another element. In fact Mosander was able to obtain two other metal oxides from it: terbium oxide (yellow) and erbium oxide (rose pink) and these he announced in 1843. This was not the end of the story, however, because later that century these too yielded other rare earth elements (aka lanthanoids). Today these elements are easily separated by a process known as liquid-liquid extraction. Continue reading from Royal Society of Chemistry
Along with other rare earth elements, terbium can be found in minerals, including cerite and gadolinite. The element can be extracted from monazite, in which it is present to the extent of 0.03 percent; from euxenite, a complex oxide containing 1 percent or more of terbia; and xenotime.
While there are not many commercial uses for terbium, sodium terbium borate is used in solid-state devices. When combined with zirconium dioxide (ZrO2), it can act as a crystal stabilizer of elevated-temperature fuel cells. Continue reading from LiveScience
