Answer to Question #84224 in Chemistry for SIMANCHAL SAHOO

Question

Explain the origin of two D-lines in the
atomic spectrum of Na

Answer 1

D-lines, in spectroscopy, a pair of lines, characteristic of sodium, in the yellow region of the spectrum. Their separation is too small to be detected with a spectroscope of low resolving power. The line is the fourth prominent absorption line in the Sun’s spectrum, starting from the red end, and accordingly is designated by the letter D. It has been resolved into two components, D1 and D2, corresponding to wavelengths 5895.924 and 5889.950 Å (angstrom = 10-10 metre), respectively.