Assertion: technetium's isotope | /r/CapableOf | consider stable - bi-209 - does decay
Facets:
value: with a half-life
type: OTHER
Source sentences:
text: It was discovered in 2003 that the isotope of bismuth then considered stable - Bi-209 - does decay, but with a half-life more than 109 times the estimated age of the universe.