<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">ytterbium</topic></authority><related type="broader"><topic>nonferrous metal</topic></related><related type="broader"><topic>elements</topic></related><variant type="other"><topic>Yb</topic></variant> <note xml:lang="en"><![CDATA[ Rare metallic element, the penultimate in the lanthanide series, having the symbol Yb and atomic number 70. Ytterbium is a soft, lustrous silver-white metal. Some of its isotopes generate gamma rays when irradiated and are used as a radiation source-substitute for portable X-ray machines. ]]></note></mads>