Correct Answer - Option 2 : 1620 year
Concept:
Decay constant:
The time required for half of the original population of radioactive atoms to decay is called the half-life.
The relationship between the half-life, T1/2, and the decay constant is given by,
\(T_{1/2}=\frac{0.693}{λ}\)
Calculation:
Given,
λ = 1.3566 × 10-11 s-1
From the above concept,
\(T_{1/2}=\frac{0.693}{λ}=\frac{0.693}{1.3566\times 10^{-11}}=5.1083\times10^{10}\ sec\)
Conversing second into the year,
\(5.1083\times10^{10}\ sec=\frac{5.1083\times10^{10}}{365\times24\times3600}=1620\ year\)