If the required excitation voltage is given, for which element the x − rays spectrum consists of three spectral lines i.e. Kα Kβ Lα :

Explanation

A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from the emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. A spectral line may be observed either as an emission line or an absorption line. Option A: The electronic configuration of Na is = 1s2,2s2,2p6,3s1 There are 2 electrons in 1st shell, 8 in 2nd and 1 in 3rd. The difference between the highest and lowest shells is 3-1=2. The spectral lines are (2,1). The two are K(alpha), and K(beta) and one is K(gamma).