Question

beam quantity is defined as the:
number of photons in the x - ray beam
average energy of the photons in the x - ray beam
average wavelength of the photons in the x - ray beam
average frequency of the photons in the x - ray beam

Explanation:

Beam quantity in an x - ray beam refers to the number of photons present. The other options pertain to characteristics like energy, wavelength, and frequency rather than quantity.

Answer:

Number of photons in the x - ray beam