14. Suppose there are 100,000 atoms of a radioactive substance that has a ½ life of 10 minutes. How many atoms will remain after 40 minutes a.2,500 b.6,250 c.12,500 d.50,000

Question

Show calculation! Thank you!

Answer 1

As the half life is 10 minutes, every 10 minutes number of atoms halves

So

t=0 100000

t = 10 100000 / 2 = 50000

t = 20 50000/2 = 25000

t = 30 25000 / 2 = 12500

t = 40 12500 / 2 = 6250

so (b)