Answer:The half-life of an element is 20 days.
Explanation:
Radioactive decay of reaction follows first order kinetics, and half life of an element is given as:
\(t_{\frac{1}{2}}=\frac{0.693}{\lambda }\)
\(\lambda\)= Decay constant
Decay constant of an element= \(\lambda = 3.411\%=0.03411 (day)^{-1}\)
\(t_{\frac{1}{2}}\) = half-life of an element
\(t_{\frac{1}{2}}=\frac{0.693}{0.03411 (day)^{-1}}\)
\(t_{\frac{1}{2}}=20.31 days\approx 20 days\)
Hence, the half-life of an element is 20 days.
