Question

A sample of old wood shows
7.0 dps/g. If the fresh sample of tree
shows 16.0 dps/g, How old is the given
sample of wood ? Half life of 4C
5730 y.
​

Answer 1

Given sample of wood is 6837.7 y  old .

Explanation:

for first order decay ,

t1/2 = 0.693/ k

k =0.693/ 5730 =  0.0001209 y⁻¹

now first order decay follows =

ln {[A₀]/[A]} = kt

t = ln {[A₀]/[A]} /k

= ㏑{16/7} / 0.0001209

= 6837.7 y