How to solve Question (Vi)?

3. Z Z Z Z a y P2 P, Figure 2 Figure 2 shows the boundary surface of 2p orbitals of a hydrogenic atom in three dimensions. (0) What are the number 2 and the letter p in the name '2p orbital stand for? (v) (vi) Describe how the px, py and pz orbitals are differentiated and named as such. Some people say that the non-spherical shapes of the orbitals in Figure 2 can only be obtained by using quantum mechanics. Do you agree? Elaborate. ******