Question

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

• A. Cu
• B. Li
• C. K
• D. Na

Answer 1

Answer: (D)

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 previous condition), ie, $3-0-1=2$.
Hence, the valence electron of the metal must present in $3 s-$ orbital.
The outer electronic configuration of the given metals is
${ }_{29} C u=3 d^{10} 4 s^{1} 3 L i=2 s^{1}{ }_{19} K=4 s^{1}{ }_{11} N a=3 s^{1}$
Thus, the given wave function corresponds to the valence electrons of the sodium metal.