Question

The half-life of 90Sr is 28 years. It is found in some steels and metals. In approximately what year was a Colt-45 Revolver machined if there is 2.16 percent of 90Sr remaining in it today?

Answer 1

Disintegration of 90sty Rate of disdegration du benda 'dt pa ㅋ 쥐고 요 지? & z ² zizt a t decay constant time for decay I Remaining ! from tao Sr No ->N - Initial tos, Ghen thy Byears We know hz 0.693 - typ OML Remaining 90s, = (2161. of No) - Put in eg. ③ +(2-16%) ghee or you

-0.693 A 100 28 to come ba (rus) years t. 154.95 years 1# $ 155 years) C 155 years has passed for 90s, to get Say we are studying in 2020, LU ear in which colt 45 was machined, +42020-155) = 1865 Colt-45 revolver was machined in 1865. Now