# What makes light to be a special part of the electromagnetic spectrum that it has a particle? [duplicate]

Why only light has photons while x-ray or micro/radio waves don't?

If we build a device that can iterate over all frequencies, what will be so special about the light range that it will start to generate photons while in all other ranges no photons will be made?

Are there special 0 mass particles for x-rays and radio waves or do they also generate photons? (the latter is highly unlikely since radio doesn't travel in a straight line)

## marked as duplicate by John Rennie, sammy gerbil, Community♦Jun 30 '18 at 19:10

• Why do you think that only visible light is made of photons? – Andrei Geanta Jun 30 '18 at 9:39
• What makes you think that? – QuirkyTurtle98 Jun 30 '18 at 9:39
• I didn't say it's made of photons, it's a wave and a particle but other parts of the spectrum aren't, why? @AndreiGeanta – shinzou Jun 30 '18 at 9:43
• All EM radiation has photons. There is nothing unique about light in this respect. – John Rennie Jun 30 '18 at 9:44
• @shinzou all EM waves travel in straight lines except when they are diffracted. Diffraction increases with wavelength so radio waves diffract more then X-rays. For more on this see Why does wavelength affect diffraction? – John Rennie Jun 30 '18 at 9:50

They are photons of mass zero and energy = to $h*ν$, where $ν$ is the frequency of the wave and $h$ is the Planck constant