What is the electric force on a proton 1.8 fm from the surface of the nucleus? hint: treat the spherical nucleus as a point charge the nucleus of a 125 xe atom (an isotope of the element xenon with mass 125 u) is 6.0 fm in diameter. it has 54 protons and charge q +54e express your answer to two significant figures and include the appropriate units. ? value units f = request answer submit part b what is the proton's acceleration? express your answer to two significant figures and include the appropriate units.