Assertion: organic nitrogen | /r/HasAspect | the formula
Facets:
Source sentences:
text: In order for plants and animals to be able to use nitrogen, N 2 gas must first be converted to more a chemically available form such as ammonium (NH 4 +), nitrate (NO 3 -), or organic nitrogen (e.g., urea, which has the formula (NH 2 ) 2 CO).