Description
تفصیل
Ytterbium (i-tur-bee-əm) is a chemical element with the symbol "Yb" and atomic number 70. A soft silvery metallic element, ytterbium is a rare earth element of the lanthanide series and is found in the minerals gadolinite, monazite, and xenotime. The element is sometimes associated with yttrium or other related elements and is used in certain steels. Natural ytterbium is a mix of seven stable isotopes.Ytterbium-169, an artificially produced isotope, is used as a gamma ray source.
Ytterbium is a soft, malleable and ductile chemical element that displays a bright silvery luster when in its pure form. It is a rare earth element, and it is readily attacked and dissolved by the strong mineral acids. It reacts slowly with cold water and it oxidizes slowly in air.
Ytterbium is quite electropositive, and it reacts slowly with cold water and quite quickly with hot water to form ytterbium hydroxide:
2 Yb (s) + 6 H2O (l) → 2 Yb(OH)3 (aq) + 3 H2 (g)
Natural ytterbium is composed of seven stable isotopes: 168Yb, 170Yb, 171Yb, 172Yb, 173Yb, 174Yb, and 176Yb, with 174Yb being the most abundant isotope, at 31.8% of the natural abundance). 27 radioisotopes have been observed, with the most stable ones being Yb-169 with a half-life of 32.0 days, 175Yb with a half-life of 4.18 days, and 166Yb with a half-life of 56.7 hours. All of its remaining radioactive isotopes have half-lives that are less than two hours, and the majority of these have half-lives that are less than 20 minutes. Ytterbium also has 12 meta states, with the most stable being Yb-169m (t½ 46 seconds).
Ytterbium was discovered by the Swiss chemist Jean Charles Galissard de Marignac in the year 1878. Marignac found a new component in the earth then known as erbia, and he named it ytterbia, for Ytterby, the Swedish village near where he found the new component of erbium. Marignac suspected that ytterbia was a compound of a new element that he called "ytterbium".
