Assuming 1 μ g of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after…

Assuming $\displaystyle 1 \mu \mathrm{~g}$ of trace radioactive element X with a half life of $\displaystyle 30$ years is absorbed by a growing tree. The amount of X remaining in the tree after $\displaystyle 100$ years is \_\_\_\_ $\displaystyle \times 10^{-1} \mu \mathrm{~g}$. [Given: $\displaystyle \ln 10=2.303 ; \log 2=0.30$ ]