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Pleasse help with this question... on half-lives?
Given that potassium contains 0.0118% potassium-40, which has half - life of 1.27 x 10 -9 yrs, calculate how many disintergrations per second there are in 1g of KCl
1 Answer
- 1 decade agoFavorite Answer
The question itself is pretty simple its just understanding it.
Right, if you have 1g of KCl then you have 0.0118% of the potassium 40. Thats like... 0.000118g of Potassium 40.
You can divide that by the mass number (40) and get how many moles then multiply it by avagadros to get how many particles you have in your sample.
Then its just a case of knowing how many particles in a year then going down to days, hours, minutes and then seconds :)
Source(s): Physics degree
