The `k_alpha` X-rays of aluminium (Z = 13 ) and zinc ( Z = 30) have wavelengths 887 pm and 146 pm respectively. Use Moseley\'s law `sqrt v = a(Z - b)` to find the wavelength of the `K_alpha` X-ray of iron (Z = 26).

Explanation

To solve the problem of finding the wavelength of the K-alpha X-ray of iron (Z = 26) using Moseley's law, we can follow these steps:

### Step 1: Understand Moseley's Law
Moseley's law states that the square root of the frequency of the X-ray is proportional to the atomic number (Z) of the element minus a constant (b):
\[ \sqrt{v} = a(Z - b) \]
where \( v \) is the frequency, \( a \) and \( b \) are constants.
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