Calculate the radius of bohr's third orbit of hydrogen atom

Explanation

To calculate the radius of Bohr's third orbit of the hydrogen atom, we can use the formula for the radius of the nth orbit in a hydrogen-like atom:

### Step-by-step Solution:

1. **Identify the Formula**:
The formula for the radius of the nth orbit (r_n) is given by:
\[
r_n = \frac{n^2 h^2}{z e^2 4 \pi m}
...