CBSE Class 11-science Answered

Shape of p orbital:

At any one energy level it is possible to have three absolutely equivalent p orbitals pointing mutually at right angles to each other. These are arbitrarily given the symbols p_x, p_y and p_z.

For example, the p orbitals at the second energy level are called 2p_x, 2p_y and 2p_z. There are similar orbitals at subsequent levels - 3p_x, 3p_y, 3p_z, 4p_x, 4p_y, 4p_z and so on.

All levels except for the first level have p orbitals. At the higher levels the lobes get more elongated, with the most likely place to find the electron more distant from the nucleus.

The smallest possible principle number for any p orbital is 2 (if n=1, then there is only a 1s orbital). If n=2 there are three p orbitals called 2px, 2py, and 2pz. The subscript indicates the axis along which the p orbital lies. The three p orbitals are identical in size, shape and energy, and they differ only in there orientation. Boundary surface diagrams indicate that the shape of the p orbitals is that of two lobes on opposite sides of the nucleus. This gives the p orbitals a ‘dumbbell’ shape. As in the case of s orbitals, p orbitals increase in size with increasing values of n.