Given the number of stationary waves is 6, i.e., the quantum number:
\[ n = 6 \]
The radius of the orbit is determined by the formula:
\[ r = \frac{n^2 \varepsilon_0^2 h^2}{\pi me^2} \]
Substituting \( n = 6 \) into the equation:
\[ r = \frac{6^2 \varepsilon_0^2 h^2}{\pi me^2} = \frac{36 \varepsilon_0^2 h^2}{\pi me^2} \]
Where: