SOLUTION: A radioactive substance decays at the rate of 12% per hour. (a)Find by trial after how many hours half of the radioactive material will be left. (b)How many hours earlier did it

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Question 1163600: A radioactive substance decays at the rate of 12% per hour.
(a)Find by trial after how many hours half of the radioactive material will be left.
(b)How many hours earlier did it have twice the current amount of radioactive material?

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!




For half of the amount remaining,

So solve



For

It would take just as long to go from twice as much to the current amount as it takes to go from the current amount to half as much. Half-life of a radioactive material is a constant for that particular element.


John

My calculator said it, I believe it, that settles it