The spectrum of sodium atom resembles the spectrum of hydrogen atom. In which way is this statement correct ?

Answer

D

Explanation

The charge of sodium (Z=11) nucleus = + 11e.
There are 2 and 8 electrons , respectively in its K and L shells [Fig. 1.16] , and there is only one electron in the outermost M -shell .
The nucleus, the K - orbit and the L - orbit in this atom, all together form an effective core and the electron in the M - orbit revolves round this core. Moreover, the charge of the core = 11e (2+8) e =+e charge of H-nucleus.
So, this electron in the M- orbit resembles the electron revolving round the nucleus in a hydrogen atom. thus , the spectrum of sodium atom resembles the spectrum of hydrogen atom.