Question

After the activity of ${}^{56}Mn$ becomes constant, number of ${}^{56}Mn$ nuclei present in the target, is equal to

• A. $5\times {10}^{11}$
• B. $20\times {10}^{11}$
• C. $1.2\times {10}^{14}$
• D. $1.8\times {10}^{15}$

Answer 1

Answer: (D)

$1.8\times {10}^{15}$

Rate of decay $=$ Rate of production
$P=\lambda N$
$N=\frac{P}{\lambda }=\frac{P\times t_{1/2}}{ln2}=1.8\times {10}^{15}$