The energy of X-ray photon is 2200 eV. Its frequency would be

5.3 × 1016 Hz 5.3 × 1017 Hz 5 × 1017 Hz 5 × 1016 Hz

5.3 × 1017 Hz

$\nu = \frac{E}{h}= \frac{2200\times1.6\times 10^{-19}}{6.63\times10^{-34}}= 5.3\times 10^{17}$