ytterbium

Japanese: イッテルビウム

Yb. Atomic number 70. Electron configuration [Xe]4f ¹⁴ 6s ^2. Lanthanide element in group 3 of the periodic table. A member of the yttrium group of rare earth elements. Atomic weight 173.04(3). Seven stable isotopes are known: mass numbers 168 (0.13(1)%), 170 (3.04(15)%), 171 (14.28(57)%), 172 (21.83(67)%), 173 (16.13(27)%), 174 (31.83(92)%), and 176 (12.76(41)%). Radioactive isotopes with mass numbers between 148 and 181 are also known. Because it is difficult to separate rare earths, the discovery of this element took many years, from CG Mosander in 1843 discovering the oxide terbia from gadolinite (formerly known as ytterbite), until it was successively split into oxides of new elements, and finally, in 1907, CFAuer von Welsbach and G. Urbain independently succeeded in isolating the element in its pure form. During that time, ytterbium was in use as the name of the element, so to avoid confusion it was renamed neoytterbium, but in 1925 IUPAC decided on ytterbium.
Abundance in the earth's crust is 2.2 ppm. It exists in minerals such as gadolinite and xenotime, and the pure metal can be obtained by electrolysis of a YbCl ₃ -NaCl molten salt mixture in a graphite bath. Density 6.965 g cm ^-3 (cubic close-packed), 6.54 g cm ^-3 (body-centered cubic). Melting point 824 °C, boiling point 1193 °C. Standard electrode potential Yb ³⁺ /Yb -2.22 V. First ionization energy 6.254 eV. Its basicity is weakest among the rare earth elements. Oxidation states 2 and 3. It is usually formed as a trivalent compound, but Yb ²⁺ can also be obtained by electrolysis. In air, Yb ²⁺ is oxidized to Yb ³⁺ . The ionic radius of the divalent compound is similar to that of Sr ²⁺ , so the solubility of the sulfate is low. The compound is diamagnetic. The trivalent compound shows properties similar to those of other rare earth elements. Yb3 ⁺ is colorless and paramagnetic. In addition to being used as an additive in optical lenses, ^169Yb is used as a gamma-ray source for non-destructive testing. [CAS 7440-64-4]

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

Japanese:

Yb．原子番号70の元素．電子配置[Xe]4f¹⁴6s²の周期表3族ランタノイド元素．希土類元素イットリウム族の一つ．原子量173.04(3)．質量数168(0.13(1)％)，170(3.04(15)％)，171(14.28(57)％)，172(21.83(67)％)，173(16.13(27)％)，174(31.83(92)％)，176(12.76(41)％)の7種の安定同位体と，質量数148～181の放射性同位体が知られている．希土類の分離は困難なため，この元素の発見は，1843年にC.G. Mosanderがガドリン石(旧名Ytterbite)から酸化物テルビアとして見いだした後，次々に新しい元素の酸化物に分割が進み，最終的に1907年にC.F.Auer von Welsbach(ウェルスバッハ)とG. Urbain(ユルバン)が独立に純粋な元素の分離に成功するまでの長年月を要した．その間にイッテルビウムが元素名として使われていたので，混乱を防ぐためにネオイッテルビウムとされたが，1925年にIUPACがイッテルビウムと決定した．
地殻中の存在度2.2 ppm．ガドリン石，ゼノタイムなどの鉱物中に存在し，純金属はYbCl₃-NaCl混合融解塩の黒鉛槽中での電解で得られる．密度6.965 g cm^－3(立方最密)，6.54 g cm^－3(体心立方)．融点824 ℃，沸点1193 ℃．標準電極電位 Yb^3＋/Yb－2.22 V．第一イオン化エネルギー6.254 eV．塩基性は希土類中でも弱い．酸化数2，3．普通，三価で化合物をつくるが，電解により Yb^2＋も得られる．空気中では Yb^2＋は Yb^3＋に酸化される．二価の化合物は，イオン半径が Sr^2＋と似ているため，硫酸塩の溶解度が小さい．化合物は反磁性である．三価の化合物は，ほかの希土類元素と同様の性質を示す．Yb^3＋は無色で常磁性である．光学レンズ用添加剤としての利用のほか，非破壊検査用のγ線源に¹⁶⁹Ybが使われている．[CAS 7440-64-4]