The half life of a radioactive substance is T . The time taken, for disintegrating 7 8 t h part of its original mass will be:

Question

The half life of a radioactive substance is T . The time taken, for disintegrating 7 8 t h part of its original mass will be:, 2 T, 3 T, T, 8 T

MARKS App · Accepted Answer

It is given that t 1 2 = T . After disintegration of 7 8 t h part, 1 8 t h part is only left. Using the decay formula, N = N 0 1 2 t t 1 2 ⇒ N 0 8 = N 0 1 2 t T ⇒ - ln 8 = - t T ln 2 ⇒ 3 ln 2 = t T ln 2 ⇒ t = 3 T

Search any question & find its solution

Looking for more such questions to practice?