How many photons are absorbed during the dental x-ray?

E=hc/wav. len

E = (6.62 x 10^-34 x 3 x 10^8) / 0.0275 x 10^-9

E = 7.22182 x 10^-15 J

To convert to eV divide by 1.6 x 10^-19

E = 7.22182 x 10^-15/1.6 x 10^-19 eV

E = 45.36 x 10^3 eV

Th energy, E, of a single x-ray photon in eV is = 45.36keV.

Number of photons, n = total energy / energy of photon

n = 3.85 x 10^-6/7.22182 x 10^-15

n = 5.33 x 10^8 photons