e18 A radioactive element has a half-life of 2.1 hours. How many hours will it take...

Question

Question

e18

A radioactive element has a half-life of 2.1 hours

Answer 1

Answer #1

Allow the element to go through several half-lives such that the total amount of time = 2. This is 4 half-lives (1/2 + 1/2 + 1/2 + 1/2 = 2):

Four half-lives:

1 ---> 1/2 ---> 1/4 ---> 1/8 ---> 1/16

Therefore it take 4 half lifes to become one-sixteenth. Therefore time taken is 4*2.1= 8.4 hours

f = 1/16

Answer 2

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