Calculate the de-Brogile wavelength of the elctron orbiting in the `n=2` state of hydrogen atom.

Explanation

To calculate the de Broglie wavelength of the electron orbiting in the n=2 state of a hydrogen atom, we can follow these steps:

### Step 1: Determine the energy of the electron in the n=2 state
The energy of an electron in a hydrogen atom is given by the formula:
\[ E = -\frac{13.6 \, Z^2}{n^2} \, \text{eV} \]
For hydrogen, \(Z = 1\) and \(n = 2\):
...