One of the major requirements of atomic structure is determination of location of electron inside an atom. The wave mechanical model establishes this in accordance with Heisenberg uncertainity principal thorugh the concept of orbitals. The orbitals are defined as that 3d's space in which probability of finding electron maximum and are represented by wavefunctions psi_(n,l,m) where n, l and m are quantum numbers. the variation of Psi is analysed in terms of polar coordinates and hence psi=f(r, theta , phi) where r' representes radius vector and theta and phi represents angle (angle) which the radius vector makes with z-axis and its projection in x-y plane makes with x-axis respectively. the expression phi_(r,theta,phi) are often given in terms of sigma instead of r where sigma =(2zr)/(na_(0)) and z=atomic number of n=shell number Which of the followings statements is incorrects with respect to psi_((r)) vs r graph for H-atoms ?