Assertion: decay's life | /r/HasProperty | 700 million years
Facets:
Source sentences:
text: But 235U has a much shorter half-life (700 million years) than 238U (4.5 billion years), so in the distant past the percentage of 235U was much higher.
text: Now the reason, one of the reasons that uranium 235 is so rare in nature is that its half life is only 700 million years, whereas the half life of uranium 238 is 4 and a half billion years.