Question 186: Atoms & Nuclei

Question

There are 10
10
radioactive nuclei in a given radioactive element, its half-life time is 1 minute. How many nuclei will remain after 30 seconds? $$\left( {\sqrt 2  = 1.414} \right)$$

Accepted Answer

$${N \over {{N_0}}} = {\left( {{1 \over 2}} ight)^{{t \over {{t^{1/2}}}}}}$$
$${N \over {{{10}^{10}}}} = {\left( {{1 \over 2}} ight)^{{{30} \over {60}}}}$$
$$ \Rightarrow N = {10^{10}} 	imes {\left( {{1 \over 2}} ight)^{{1 \over 2}}} = {{{{10}^{10}}} \over {\sqrt 2 }} \approx 7 	imes {10^9}$$

Answer

2 $$	imes$$ 10
10

Answer

7 $$	imes$$ 10
9

Answer

10
5

Answer

4 $$	imes$$ 10
10

Atoms & Nuclei

There are 10 10 radioactive nuclei in a given radioactive element, its half-life time is 1 minute. How many nuclei will remain after 30 seconds? $\left( {\sqrt 2 = 1.414} \right)

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