Question

What fraction of a given sample of radioactive nuclide remains after four half lives??

Answer 1

@kelly226

Answer 2

1 half-life: 1/2 left

2: half of that, or 1/4

3: half of that, or 1/8

4: half of that, or 1/16

In general: (1/2)^x, where x is the number of half-lives.

Answer 3

After one half life, half of the substance is gone.

After another half life, half of the remaining amount is gone. So you have (1/2)*(1/2) = 1/4 of the amount left over


After another half life, half of the remaining amount is gone. So you have (1/2)*(1/2)*(1/2) = 1/8 of the amount left over

See where this is going?

Answer 4

THANKS!