Two particles of equal but unknown charge are held 45 cm apart. If their electrostatic repulsion is 2.2 x 10^5 Newtons, what is the magnitude of their charge?

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Atomic nuclei of almost all elements consist of

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.