Answer: 1.32 x 10^-9 m
Explanation:
The formula for the radius of nth orbital is:
[tex]r_{n}=\frac{n^{2}}{Z} \times 0.528 \text { Angstorms }[/tex]
For hydrogen, Z= 1, so we have:
[tex]$\begin{aligned}r_{n} &=5^{2} \times 0.528 \text { Angstorm } \\&=13.2 \text { Angstorms } \\&=13.2 \times 10^{-10} \mathrm{~m} \\&=1.32 \times 10^{-9} \mathrm{~m}\end{aligned}$[/tex]
