Assertion: borax's boron | /r/HasProperty | prepared
Facets:
value: by heating the trioxide
type: MANNER
value: by reducing volatile boron halides
type: MANNER
Source sentences:
text: Pure boron can be prepared by reducing volatile boron halides with hydrogen at high temperatures.
text: Impure (amorphous) boron can be prepared by heating the trioxide (O 3 ) with magnesium powder.