Assertion: baryon's quark | /r/HasAspect | a charge of -1/3
Facets:
Source sentences:
text: Protons (which have a total charge of +1) are made of two up quarks (which have a charge of +2/3) and one down quark (which have a charge of -1/3).
text: One down quark has a charge of -1/3, and two up quarks have a charge of +2/3 each.
text: Down quarks have a charge of -1/3.