The radial probability distribution curve obtained for an orbital wave function ($\mathrm{\psi }$) has 3 peaks and 2 radial nodes. The valence electron of which one of the following metals does this wave function ($\mathrm{\psi }$) correspond to ?

Since the radial probability distribution curve has 3 peaks, it means that for it n=3 and l=0. Moreover, it has two radial nodes ie, n−l−1=2, which also satisfied the previous condition, ie, 3−0−1=2. Hence, the valence electron of the metal must present in 3s−orbital

Valence shell electronic configurations of given options are,

Cu - [Ar]3d¹⁰4s¹

Li - [He]2s¹

K - [Ne]4s¹

Na - [He]3s¹

Hence 'Na' is the suitable answer.