A) 3.70 g
B) 6.30 g
C) 1.35 g
D) 2.50 g
Correct Answer: C
Solution :
Mean life \[\tau =\frac{1}{\lambda },\,\lambda \] beings decay constant. Also time given \[t=2\tau =2\times \frac{1}{\lambda }=\frac{2}{\lambda }\] Thus, mass remained after time t is \[M={{M}_{0}}\,{{e}^{-\lambda t}}\] \[=10\,{{e}^{-\lambda +\frac{2}{\lambda }}}(\because \,\,{{M}_{0}}=10g)\] \[=10\,{{e}^{-2}}=\frac{10}{{{e}^{2}}}=1.35\,g\]You need to login to perform this action.
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