Assertion: oxygen | /r/HasProperty | pure element
Facets:
Source sentences:
text: Oxygen is a pure element, while the air people breathe is a mixture of elements.
text: Oxygen is a pure gaseous element.
text: Oxygen is pure when a certain mass (or volume) of it contains no other elements.
text: Oxygen is a pure gas element.
text: Oxygen is a pure element, while the air we breathe is a mixture of elements.
text: Oxygen is a pure gaseous element.