sorry i don't get it..
do i just
1.68*10^-5kg * 6.02*10^23/40 = 2.5284*10^17
and then sub this into the equation R=0.653N/half-life??
but the answer i get from this is 4.36*10^-3
which i think there is still something wrong in ym calculation...
Help! calculating the the activity of a radioactive sample!
1. find activity R
2. the average 70 KF males contain 140 gram of potassium. of this 0.012% is potassium 40. the half life of potassium 40 is 1.2 billion years. so how many K40 decay per second and what is the activity of K40 in...