For 3s orbital of hydrogen atom, the normalized wave function is given by  ${\phi }_{3s}=\frac{1}{81\sqrt{3\pi }}{\left(\frac{1}{a_0}\right)}^{3/2}[27-\frac{18r}{a_0}+\frac{2r^2}{a_0^2}]e^{\frac{r}{3a_0}}$
The above mentioned orbital (3s) has two spherical nodes at$2a_0$ and $x{a}_0$ . Find the value of x/4 [Use: $3\sqrt{3}=5$]