Question

Hospital x-ray generators emit x-rays with wavelength of about 15.0 nanometers (nm), where 1nm=10−9m. what is the energy of a photon of the x-rays?

Answer 1

A photon is characterized by either a wavelength, denoted by λ or equivalently an energy, denoted by E. There is an inverse relationship between the energy of a photon (E) and the wavelength of the light (λ) given by the equation: E=hc/λ E=hc/λ where h is Planck's constant and c is the speed of light. The value of these and other commonly used constants is given in the constants page. h = 6.626 × 10 -34 joule·s c = 2.998 × 108 m/s By multiplying to get a single expression, hc = 1.99 × 10-25 joules-m E=hc/λ (6.626*10^-34 J*s) x (2.998×10^8m/s)/ 1.5*10^-8 m = 1.32*10^-17 J