Assertion: boron | /r/HasProperty | discovered by l. j. thénard
Facets:
value: in 1808
type: TEMPORAL
Source sentences:
text: Boron is a metalloid and was discovered by Joseph L. Gay-Lussac and L. J. Thénard in 1808.
text: Boron was discovered by Joseph L. Gay-Lussac and L. J. Thénard in 1808 that was around 60% pure.