Definition of "ytterbium"

At a meeting of the Russian Chemical Society held October 20, 1881 (and reported in the Bulletin de la Société Chimique de Paris, for August, 1882), Mendelejeff [Dmitri Mendeleev], the distinguished author of the periodic law, remarked that only two of the recently announced elements—scandium and ytterbium—had been satisfactorily confirmed. These have been obtained in a pure state by [Lars Fredrik] Nilson, and neither of them has absorption spectra.

1883, H[enry] Carrington Bolton, “List of New Elements Announced since 1877”, in An Account of the Progress in Chemistry in the Year 1882. [...] From the Smithsonian Report for 1882, Washington, D.C.: Government Printing Office, page 6

The lanthanides samarium, europium and ytterbium possess relatively stable and long-known dispositive states.

1991, John D. Corbett, “Coproportionation Routes to Reduced Lanthanide Halides”, in G[erd] Meyer, L[ester] R. Morss, editors, Synthesis of Lanthanide and Actinide Compounds (Topics in F-element Chemistry; 2), Dordrecht: Kluwer Academic Publishers, page 160

Ytterbium is a silvery, soft, malleable, and ductile metal with a lustrous metallic shine. It is slightly reactive in air or water at room temperatures. Ytterbium is located next to last of the rare-earths in the lanthanide series.

2006, Robert E. Krebs, “Guide to the Elements”, in The History and Use of Our Earth's Chemical Elements: A Reference Guide, 2nd edition, Westport, Conn.: Greenwood Press, page 301

Microstructural optical fibers have been developed that have utilized phosphate-based glasses due to their ability to solubilize rare earth components such as ytterbium, which give the fibers their high light absorption and amplification per unit length.

2015, E. A. Abou Neel, V. Salih, J. C. Knowles, “Phosphate-based Glasses”, in Paul Ducheyne, editor, Comprehensive Biomaterials, volumes I (Metallic, Ceramic and Polymeric Biomaterials), Amsterdam: Elsevier, page 289