Assertion: nitrogen dioxide's gas | /r/HasProperty | hydrogen
Facets:
value: according to the national balloon museum
type: OTHER
Source sentences:
text: The first gas balloon flight was launched in Paris in 1783 and the gas used in the balloon was hydrogen, according to the National Balloon Museum.
text: The principal gases provided are nitrogen, oxygen, carbon dioxide, argon, hydrogen, helium and acetylene, although many other gases and mixtures are also available in gas cylinders.
text: industrial gases”  is sometimes narrowly defined as just the major gases sold, which are: nitrogen, oxygen, carbon dioxide, argon, hydrogen, acetylene and helium.