Question

The Bohr's radius for the fifth orbit of the hydrogen atom will be:

• A. 0.529 A
• B. 2.645 A
• C. 13.225 A
• D. none of above

Answer 1

The correct option is C 13.225 A

$r_n=r_0\times n^2$
$r_5=(0.529\times {10}^{-10})\times \left(5^2\right)$ m
$=13.25\times {10}^{-10}\times (5{)}^2$ m
$=13.225\times {10}^{-10}m=13.225A^0$