You find a bag labeled 10 kg of lead210 Its contents now wei

You find a bag labeled \"10 kg of lead-210\". Its contents now weigh 1.25 kg. How many half-life periods have there been since the bag was weighed and labeled? Lead-210 is a radioisotope with a half-life of about 22 years.

1/8

1/4

4

3

Solution

half life is the amount of period required for a compound/atom to reach half its initial quantity.

To start with we had 10 kg of Pb-210;

after 1st hlf life we would have 5kg;

2.5kg after 2nd half life;

1.25kg after 3rd half life

Therefore, 3 half lives for the initial