For a particular atomic orbital, the plot of the radial wavefunction ( _r ) against the distance from the nucleus ( r ) starts from the origin ( _r = 0 at r = 0 ) and crosses the r -axis exactly once. Which of the following orbitals is represented by this plot?

Step-by-step solution

The radial wavefunction _r starting from the origin ( _r = 0 at r = 0 ) indicates that the orbital is not an s -orbital. For s -orbitals ( l = 0 ), the probability density is maximum at the nucleus, so _r 0 at r = 0 . Thus, l > 0 . The curve crossing the r -axis exactly once means there is 1 radial node. The number of radial nodes is given by the formula: n - l - 1 . Let us check the given options: 2s : l = 0 (does not start at origin), radial nodes = 2 - 0 - 1 = 1 . 3s : l = 0 (does not start at origin), radial no