Semi-empirical mass formula and liquid drop model

[matt222]

Dear all can anyone explain to me the semi-empirical mass formula and liqiud drop model, I really don't understand what is the difference between them and which one came before the other. I really confused

 

[law&theorem]

refer to wiki
http://en.wikipedia.org/wiki/Semi-empirical_mass_formula#The_liquid_drop_model_and_its_analysis

 

[Thermalne]

This is a better question for the Nuclear Particles subforum.