An alpha particle of energy 5 MeV is scattered through 180° by a fixed uranium nucleus. The distance of the closest approach is of the order of
10-15 cm
10-13 cm
10-12 cm
10-19 cm
Use E=14πε0(Ze)(e)r0 5×1.6×10-13=9×109×2×92×1.6×10-192r0 r0=5.3×10-14m≈10-12cm