How does the electrical force relate to the distance between two charged objects

Which property of fossils allow scientists to determine the relative rock ages..

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.