Answer:
this subject takes time. i would study nonstop. past year i was 1 of 10 that passed our chemistry class with 200 people in it. it just takes time
Answer:
You do well. what a long question
First off there are some issues in your questions but I can still help in answering this type of problem. First, there is no Sr-20. The 4 abundant form includes Sr-84, Sr-88, Sr-87, Sr-86, Sr-84.
More importantly, the half life of strontium must be given.
For demonstration sake, let us assume Sr-85 is the isotope. It has a half-life of 64.853 days and I'm assuming the units of 87.3 is in days.
A/Ao = e^-(ln2/t)T
where A- final amount Ao -initial amount t- halflife T-total time elapsed
% = <span>e^-(ln2/64.853)(87.3) = 0.3933 or 39.33%
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