For a given element the wavelength of the `K_alpha`- line is 0.71 nm and of the `K_beta`- line it is 0.63 nm. Use this information to find wavelength of the `L_alpha` line.

Explanation

To find the wavelength of the `L_alpha` line using the given wavelengths of the `K_alpha` and `K_beta` lines, we can follow these steps:

### Step 1: Understand the relationship between the energies of the lines
The energies of the X-ray lines are related as follows:
- The energy of the `L_alpha` line is equal to the energy of the `K_beta` line minus the energy of the `K_alpha` line.

### Step 2: Write the formula for energy in terms of wavelength
The energy \( E \) of a photon can be expressed using the formula:
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