The half-life of a radioactive isotope X is 20 yr . It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio 1 : 7 in a sample of a given rock. The age of

Question

The half-life of a radioactive isotope X is 20 yr . It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio 1 : 7 in a sample of a given rock. The age of the rock is estimated to beNEET 2013 (All India)

TestHub · Accepted Answer

( As N 0 ​ N ​ = ​ ( 2 1 ​ ) n N 0 ​ N ​ = ( 2 1 ​ ) 3 = 8 1 ​ ​ Number of half lives = 3 ⇒ ∴ ​ T T ​ = 20 yr = n t ​ ​ or t = T × n = 20 × 3 yr = 60 yr

Physics - Modern Physics Question with Solution | TestHub

Options:

Doubts & Discussion