Question

Radius of first orbit of hydrogen is $0.53\dot{A}$. The radius in fourth orbit is:

• A. $8.48\dot{A}$
• B. $2.12\dot{A}$
• C. $4.24\dot{A}$
• D. $0.193\dot{A}$

Answer 1

The correct option is A $8.48\dot{A}$

$r_n\propto n^2$
$\frac{r_4}{r_1}={\left[\frac{4}{1}\right]}^2=16$
$r_4=16\times 0.53$
$=8.48\dot{A}$