(4.6) Would you expect the surface energies of the Noble-gas solids to be greater than, about the same as, or smaller than those of ionic crystals? Explain.

I've included the book's definition of surface energy:

4.5 Surface Energy The surface energy 7 of a solid is the amount of energy needed to create a unit area of new surface. The process can be pictured as shown in Fig. 4.7a, where two new surfaces are created by cutting a solid in two. Given this simple picture, the surface energy is simply the product of the number of bonds N, broken per unit area of crystal surface and the energy per bond Ebond, or y=N, Ebond (4.15)