Assertion: manganese | /r/HasProperty | discovered by johan gottlieb gahn
Facets:
value: by heating the mineral pyrolusite
type: MANNER
Source sentences:
text: Proposed to be an element by Carl Wilhelm Scheele in 1774, manganese was discovered by Johan Gottlieb Gahn, a Swedish chemist, by heating the mineral pyrolusite (MnO 2 ) in the presence of charcoal later that year.