+3 votes
in Chemistry by kratos

The activity per ml of a solution of radioactive substance is x. How much water be added to 200 ml of this solution so that the acitivity falls to x/20 per ml after 4 half-lives ?

(A) 100ml

(B) 150ml

(C) 80ml

(D) 50ml.

1 Answer

+1 vote
by kratos
 
Best answer

Correct Answer is: (D) 50ml.

V = 250ml.

So added volume of water = 50ml.

...