Ytterbium
. Ytterbium, symbol Yb, soft, malleable, ductile metallic element that has a bright, silvery luster. Ytterbium is one of the rare earth elements in the lanthanide series of the periodic table . The atomic number of ytterbium is 70. In 1878, the Swiss chemist Jean Charles de Marignac separated a new substance from the rare earth elements and named it ytterbium. In 1907 and 1908, however, the French chemist Georges Urbain and the Austrian chemist Carl Auer von Welsbach independently separated Marignac's ytterbium into two elements, which are now called ytterbium and lutetium . Ytterbium is reasonably stable but reacts slowly with water to liberate hydrogen. Ytterbium occurs in combination with such minerals as xenotime, euxenite, monazite, and gadolinite. It ranks about 44th in natural abundance among the elements in the earth's crust. Ytterbium has potential applications in alloys , electronics , and magnetic materials. Ytterbium melts at 819° C (about 1506° F), boils at about