1 x-ray photon equals how many light photons?

1 x-ray photon equals how many light photons?

• A. One light photon
• B. Ten light photons
• C. Hundreds of light photons
• D. Thousands of light photons

Answer: (D)

A single x-ray photon carries far more energy than a visible-light photon. Photon energy scales inversely with wavelength (E = hc/λ), so because x-rays have much shorter wavelengths than visible light, their energy is much higher. When you think in terms of energy—how much energy would need to be supplied by visible photons to match one x-ray photon—the number is huge. For typical x-ray energies (tens of keV) and visible-light energies (a few eV), one x-ray photon contains enough energy to equal thousands (often tens of thousands) of visible photons. That’s why the correct idea is that one x-ray photon is equivalent to thousands of light photons in energy, even though it’s just a single high-energy photon.

A single x-ray photon carries far more energy than a visible-light photon. Photon energy scales inversely with wavelength (E = hc/λ), so because x-rays have much shorter wavelengths than visible light, their energy is much higher. When you think in terms of energy—how much energy would need to be supplied by visible photons to match one x-ray photon—the number is huge. For typical x-ray energies (tens of keV) and visible-light energies (a few eV), one x-ray photon contains enough energy to equal thousands (often tens of thousands) of visible photons. That’s why the correct idea is that one x-ray photon is equivalent to thousands of light photons in energy, even though it’s just a single high-energy photon.