# I don’t understand this question

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#1
A radioactive isotope has a count rate 0f 6400Bq and a half life of 4days. What fractionof the isotope will have decayed after 20 days? What will the count rate now be?
0
11 months ago
#2
(Original post by Yaaay)
A radioactive isotope has a count rate 0f 6400Bq and a half life of 4days. What fractionof the isotope will have decayed after 20 days? What will the count rate now be?
What does the half-life mean?
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11 months ago
#3
(Original post by Muttley79)
What does the half-life mean?
The time taken for the radioactivity to halve.
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11 months ago
#4
(Original post by Dee-Emma)
The time taken for the radioactivity to halve.
Yes I know - I was asking the OP -
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11 months ago
#5
(Original post by mpaprika)
half life
I think it's better to give hints ...
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11 months ago
#6
(Original post by Muttley79)
I think it's better to give hints ...
oh, oops - sorry
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11 months ago
#7
theres a gcse method and an a level method for this. R u GCSE or A level?
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11 months ago
#8
(Original post by Sophhhowa)
theres a gcse method and an a level method for this. R u GCSE or A level?
Given that 20 is divisible by 4, it's easy. There's no point in using a more complicated approach than the question requires.
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11 months ago
#9
(Original post by RogerOxon)
Given that 20 is divisible by 4, it's easy. There's no point in using a more complicated approach than the question requires.
Yes I suppose but an A level student may benefit from being aware of the other method. However, considering it’s divisible I suspect this is GCSE so ignore me
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