Question 60: Atoms & Nuclei

Question

Ba-122 has half-life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. It initially 80 g at Ba-122 was taken, how much Ba was left when experiment was started?

Accepted Answer

Given, n = 2 min to 10 min = 5 half-lives and $$N_0=80$$ g
We know, $${N \over {{N_0}}} = {\left( {{1 \over 2}} \right)^n}$$
$$ \Rightarrow N = {{{N_0}} \over {{2^n}}} = \left( {{{80} \over {{2^5}}}} \right) = {{80} \over {32}} = 2.5\,g$$

Answer

2.5 g

Answer

5 g

Answer

10 g

Answer

20 g

Atoms & Nuclei

Ba-122 has half-life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. It initially 80 g at Ba-122 was taken, how much Ba was left when experiment was started?

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