Plz explain this.

Plz explain this. 2s orbital 0.05 Ttr 10 15 20 25 r (units of Bohr radius / Z) Figure 2.6 (a) Plot of 4111-2 V 2 versus r for 2s orbitals of huirogen enra

Dear student,

From the graph , the radial probability density ( $\psi$²) at first approaches to zero at and then increases again its value of r. This showes that 2s - orbitals has one nodal plane. 
Regards