Assertion: tin's form | /r/HasProperty | metallic
Facets:
Source sentences:
text: β-tin (the metallic form, or white tin, BCT structure), which is stable at and above room temperature, is malleable.
text: In contrast, α-tin (nonmetallic form, or gray tin), which is stable below 13.2 °C (55.8 °F), is brittle.