The Wavefunction for the 2s Orbital in Hydrogen Is Given $R_{2 s}=\frac{1}{2 \sqrt{2}}\left(\frac{Z}{a_{0}}\right)^{3 / 2}(2-\sigma) \exp (-\sigma / 2) \text { where } \sigma=\frac{\mathrm{Zr}}{a_{0}}$

The wavefunction for the 2s orbital in hydrogen is given by $R_{2 s}=\frac{1}{2 \sqrt{2}}\left(\frac{Z}{a_{0}}\right) ^{3 / 2}(2-\sigma) \exp (-\sigma / 2) \text { where } \sigma=\frac{\mathrm{Zr}}{a_{0}}$ At what radius is there a node?

A) r = 0
B) r = 2/a₀
C) r = a₀
D) r = 2a₀
E) there are no radial nodes in this function