Atomic Rayleigh scattering of photons in the momentum-transfer range 0 − 1 0 m c

The new results of measurements of coherent scattering of photons by bound atomic electrons over a momentum transfer $q$ range $0\ensuremath{-}4mc$ together with those from other recent measurements with a coverage in the momentum transfer up to $10mc$ are presented for a critical evaluation of the previous and new calculations on Rayleigh scattering. This evaluation reveals the ranges of applicability of the form-factor formalism in the nonrelativistic and relativistic domain and demonstrates the trend of behavior of the exact theoretical predictions as a function of $\frac{q}{\ensuremath{\alpha}\mathrm{Zm}}$.