Assertion: metal's oxide | /r/HasProperty | tio
Facets:
Source sentences:
text: The most important oxide is TiO 2 , which exists in three important polymorphs; anatase, brookite, and rutile.
text: The oxides TiO 2 , ZrO 2 and HfO 2 are white solids with high melting points and unreactive against most acids.