Answers

2015-09-26T14:39:34+05:30
Half life, T_{0.5} = 19.7 minutes

T_{0.5}= \frac{0.693}{\lambda} \\ \\ \Rightarrow \lambda= \frac{0.693}{T_{0.5}} \\ \\ \Rightarrow \lambda= \frac{0.693}{19.7} =0.035\ min^{-1}

A₀ = 1g
t = 78.4 second
A = ?

A = A_oe^{-\lambda t}\\ \\ \Rightarrow A = 1 \times e^{-0.035 \times 78.4}\\ \\ \Rightarrow A =0.064\ g

After 78.4 minute, 0.064g 214Bi will be left.
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