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A sample of an unknown radioisotope exhibits 8540 decays per second After 350 minutes the number of decays has decreased to 1250 per second What is the half life?
Wiki User
∙ 14y ago
The decay rate N at time t is N(t)=N(0) x 2^-(t/t_half), where t_half is the half life and N(0) is the decay rate at t=0. The ^ means "to the power of."
You can solve this for t_half:
t_half = - t / log_2(N(t)/N(0)) (log_2 means logarithm base 2)
N(350 minutes)=1250, N(0)=8540. The rest is just finding a calculator to give you log_2 of 1250/8540.
Wiki User
∙ 14y ago
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