Question 399: Atoms & Nuclei

Question

A radioactive substance has half-life of 60 minute. During 3 hour, the amount of substance decayed would be

Accepted Answer

$$\begin{aligned}
& N=N_0\left(\frac{1}{2}ight)^{\frac{1}{\pi / 2}} \
	herefore \quad & \frac{N}{N_0}=\left(\frac{1}{2}ight)^{\frac{1}{\pi^{T / 2}}}
\end{aligned}$$
$$\begin{aligned}
&\begin{array}{ll}
	herefore & \frac{\mathrm{N}}{\mathrm{~N}_0}=\left(\frac{1}{2}ight)^{\frac{3 	imes 60}{60}}=\left(\frac{1}{2}ight)^3 \
	herefore & \frac{\mathrm{~N}}{\mathrm{~N}_0}=\frac{1}{8}
\end{array}\
&	ext { The amount of substance decayed }=1-\frac{\mathrm{N}}{\mathrm{~N}_0}\
&1-\frac{N}{N_0}=1-\frac{1}{8}=\frac{7}{8}=87.5 \%
\end{aligned}$$

Answer

$8.5 \%$

Answer

$25 \%$

Answer

$12.5 \%$

Answer

$87.5 \%$

Atoms & Nuclei

A radioactive substance has half-life of 60 minute. During 3 hour, the amount of substance decayed would be

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