Assertion: hydrogen | /r/HasAspect | three common isotopes
Facets:
value: according to jefferson lab
type: OTHER
Source sentences:
text: Hydrogen has three common isotopes: protium, which is just ordinary hydrogen; deuterium, a stable isotope discovered in 1932 by Harold C. Urey; and tritium, an unstable isotope discovered in 1934, according to Jefferson Lab.
text: Hydrogen has three common isotopes.