<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>3633</termId><termName>Elementos químicos</termName><termType>PT</termType><termCreatedDate>2014-09-15 19:38:45</termCreatedDate><relation><relationType>UF</relationType><termId>3634</termId><termName>Cuerpos simples</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>3590</termId><termName>Química</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>3635</termId><termName>Metales</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>3689</termId><termName>Metaloides</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>568</termId><termName>Tabla periódica (Química)</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>7335</termId><termName>Catalizadores</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>8196</termId><termName>Isótopos</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>13960</termId><termName>Átomos</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>18497</termId><termName>Carbono</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>18498</termId><termName>Hidrógeno</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>13265</termId><termName>Oligoelementos</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>18322</termId><termName>Valencia (Química)</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>28709</termId><termName>Productos químicos</termName><termType>PT</termType></relation></term>  </Zthes>