Ytterbium
Ytterbium is a chemical element.  It has the chemical symbol Yb.  It has the atomic number 70 which means it has 70 protons in an atom. It is part of a group of chemical elements in the periodic table named the Lanthanides. Ytterbium, along with yttrium, terbium, and erbium, is one of the four elements to be named after the town of Ytterby in Sweden, all of which are rare earth elements. It is soft and silver in colour.