Given that \(\rm \psi_{n,l,m}(r, \theta, \phi)=R_m(r)Y_m(\theta, \phi); R_{20}(R)\) ∝ \( \left(2-\frac{r}{a_0}\right)e^{-\frac{r}{a_0}}, Y_{00}(\theta, \phi)=1/\sqrt{4\pi}\) the position of radial node in the 2s orbital is at