<?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">periodic table</topic></authority><related type="other"><topic>elements</topic></related><related type="broader"><topic>tables</topic></related><variant type="other"><topic>periodic table of the elements</topic></variant> <note xml:lang="en"><![CDATA[ A standardized chart of the chemical elements laid out in sequence by atomic number, arranged in horizontal rows and vertical columns, called periods and groups, so that elements with similar properties are in the same column. ]]></note></mads>