I need help, please answer

__can be defined as which velocity changes

What is the binding energy of a nucleus that has a mass defect of 5.81*10-^29 kg a 5.23*10-^12 j b 3.15* 10^12 j c 1.57*10-3 j d 9.44*10^20 j

Which process describes vaporization that takes place below the surface of a liquid? condensation melting boiling evaporation