Assertion: occurring krypton | /r/MadeOf | six stable
Facets:
Source sentences:
text: Naturally occurring krypton is made of six stable and one slightly radioactive isotope.
text: Naturally occurring krypton is made of five stable isotopes and one (78
text: Naturally occurring krypton is composed of six stable isotopes.
text: Naturally occurring krypton in Earth's atmosphere is composed of five stable isotopes, plus one isotope (78Kr) with such a long half-life (9.2×1021 years) that it can be considered stable.