Answer:
3.125% will remain after 125 days
Explanation:
Given data:
Half life of Th-234 = 25 days
Percent of thorium remain after 125 days = ?
Solution:
Number of half lives = T elapsed / half life
Number of half lives = 125 days / 25 days
Number of half lives = 5
At time zero =100%
At 1st half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At third half life = 25%/ 2 = 12.5%
At 4th half life = 12.5% /2 = 6.25%
At 5th half life = 6.25% /2 = 3.125%
