SOLUTION: A scientist has 100 grams of a substance where half of it decays every hour. Write an equation to determine how long it takes until 25 grams are remaining

Question 844689: A scientist has 100 grams of a substance where half of it decays every hour. Write an equation to determine how long it takes until 25 grams are remaining
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!

 

Hi,

Q(t) = 

first find k

 .5 = 

 ln(.5)/-1 = k = .6931

25 = 

 .25 = 

  = t

  

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