Assertion: phosphorus's allotrope | /r/HasProperty | obtained
Facets:
value: industrially
type: LOCATION
value: by heating at 300 c
type: TEMPORAL
Source sentences:
text: Black allotrope is obtained industrially by heating at 300 C under pressure with a mercury catalyst.
text: Black allotrope is obtained industrially by heating at 300 C under pressure with a mercury catalyst.
text: Black allotrope is obtained industrially by heating at 300 C under pressure with a mercury catalyst.