Physics · Atoms

Experimentally it is found that 12.8 eV energy is required to separate a hydrogen-like atom into a proton and an electron from a certain bound state. If its total energy is −12.8 eV, the orbital radius of the electron is 9x × 10−10 m. The value of x is ________. (Take 1 eV = 1.6 × 10−19 J, 14πε0 = 9 × 109 N·m2/C2, and electronic charge = 1.6 × 10−19 C)