What are the formulas for half-life in exponential decay?
1 Answer
Sep 15, 2014
The formulas for half-life are
The equation for exponential decay is
(1)
We can solve this for
(2)
And the formulas for half-life
(3)
and
(4)
If you know the value of
EXAMPLE
Technetium-99m is used for brain scans. If a laboratory receives a shipment of
200 g of this isotope and only 12.5 g of this isotope remain after 24 h, what is the half-life of technetium-99m?
Solution