<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31343585</termId><termName>lithium</termName><termType>PT</termType><termNote><![CDATA[ Pure metallic element having symbol Li and atomic number 3; a soft, silver-white metal, the lightest element in the alkali metal series. It is obtained from minerals, such as spodumene, in which it occurs or as a byproduct of potash and borax. Use also for this metal as processed and formed for use as a heat transfer medium in nuclear reactors or as a strengthener in alloys and many manufactured products such as ceramics and glass. Its salt is used in psychiatric medications.   ]]></termNote><termCreatedDate>2026-03-30 20:32:40</termCreatedDate><relation><relationType>UF</relationType><termId>31343586</termId><termName>Li</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31375243</termId><termName>nonferrous metal</termName><termType>PT</termType></relation><relation><relationType>BT</relationType><termId>31319740</termId><termName>elements</termName><termType>PT</termType></relation></term>  </Zthes>