SOLUTION: The half-life of Calcium-47 is 4.536 days. What is the daily decay rate? Give your answer in both decimal and percent form. a) As a decimal, the daily decay rate is _____?

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Question 1129328: The half-life of Calcium-47 is 4.536 days. What is the daily decay rate? Give your answer in both decimal and percent form.
a) As a decimal, the daily decay rate is _____?
Found 2 solutions by greenestamps, josgarithmetic:
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


If the half life is 4.536 days, then 1 day is 1/4.536 of a half life.

Then the amount left after 1 day is

%28.5%29%5E%281%2F4.536%29 = 0.8583 to 4 decimal places.

The daily decay rate is then 1-0.8583 = 0.1417.

The decay rate as a decimal is 0.1417; as a percent it is 14.17%.

Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
y=p%2Ab%5Ex
y, amount present after x days
p, initial amount

y=p%2Ab%5Ex(

Half-life in days, 4.536
1%2F2=b%5E4.536
log%28%281%2F2%29%29=4.536%2Alog%28%28b%29%29
log%28%28b%29%29=log%28%281%2F2%29%29%2F4.536

b=0.8583, each day 0.8583 fraction is retained; 0.1417 fraction is decayed.

14.17% decay per day.