hhjuhyfdrtyu2929 hhjuhyfdrtyu2929 28-11-2022 Chemistry contestada The uranium present in earth today is 99.28% 238U and 0.72% 235U. The half-lives are 4.51*109 years for 238U and 7.0*108 years for 235U. How long ago was this uranium 50%238U and 50% 235U?
