Assertion: metal's compound | /r/HasProperty | known since ancient times
Facets:
Source sentences:
text: Antimony compounds have been known since ancient times and were used for cosmetics, metallic antimony was also known but mostly identified as lead.
text: The most common compound of chlorine, sodium chloride (table salt), has been known since ancient times; however, around 1630, chlorine gas was obtained by the Belgian chemist and physician Jan Baptist van Helmont.