The wavelength of `k_alpha` line in the X-ray spectrum for tungsten (Z=74) is 200 Å. What would be the wavelength of same line for platinum Z =78 ?

Explanation

To solve the problem of finding the wavelength of the K-alpha line for platinum (Z=78) given the wavelength for tungsten (Z=74) is 200 Å, we can follow these steps:

### Step 1: Understand the relationship between wavelength and atomic number
The wavelength of the K-alpha line in X-ray spectra can be related to the atomic number (Z) using the formula:
\[ \nu = A^2 (Z - B)^2 \]
where \(A\) and \(B\) are constants. For K-alpha transitions, \(A\) is typically taken as \(3R_c/4\) and \(B = 1\).
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