Determine the approximate wavelength (with an accuracy of 10%) of the highest energy X-ray in the characteristic spectrum of copper.
1
\( 1.14 \, \text{Å} \)
2
\( 1.24 \, \text{Å} \)
3
\( 1.28 \, \text{Å} \)
4
\( 1.34 \, \text{Å} \)
Determine the approximate wavelength (with an accuracy of 10%) of the highest energy X-ray in the characteristic spectrum of copper.