Question

Which term of the bethe-weizsäcker formula for the nuclear binding energy is associated to the nuclear surface?

Answer 1

Nucleons on surface of nucleus experience attractive forces only from one side of the surface,
thus nucleons on surface have lesser binding energy.
 This decrease is proportional to the
number of nucleons on the surface/to surface area of the nucleus.  

contribution of surface effect to binding energy of the nucleus may be expressed as