NEET 2020 Model Question Paper 3

If in the rock there is no Y element, then the time taken by element X to reduce to 1/8 th the initial value w ill be equal to

1

8

=(

1

2

)n or n=3; Therefore, from the beginning three half life time is spent. Hence the age of the rock is =λN=λN0(

1

2

)

9

3

=

λN0

8