# What is an X ray photon?

Discussion in 'General Discussion' started by SoSolid, 21 May 2006.

1. SoSolid

# Location: The Moon

Is an X ray photon an electron?

# Location: London

no, its still a photon, a light particle.

3. SoSolid

# Location: The Moon

But aren't X rays electrons that have lost energy and the release of energy is the x ray?

4. daz

# Location: Bucks

X-rays are photons generated by firing electrons at metal.

# Location: London

The release of electromagnetic energy is the x ray. This is a photon. Photons and electrons are two different particales, aand as you yourself asked if an X ray photon is an electron.

http://en.wikipedia.org/wiki/X_rays

6. SoSolid

# Location: The Moon

It's just that I am stuck on an A level physics question which gives me the energy of an x ray photon and asks me to calculate the speed of it. I was thinking if an x ray was an electron I could use e=mc^2 I can't think of any other way to work out the speed without knowing its wavelength or frequency?

7. PhilthyPhil

# Location: UK

It's a photon so its speed=c

Last edited: 21 May 2006
8. MrMatteh

# Location: Essex

an x-ray photon would just just be a photon with a wavelength of what... 10^-9 - 10^-10

you can calculate the frequency of them using f=c/λ

not sure why you are being asked to work out the speed.. its a constant

then just use e=hf to find the energy

or just e=hc/λ

an x-ray is just a photon with a specific wavelength

just like radio waves are.. and visible light etc...

edit: convenient: http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html
check your answer against that (its in eV though, so don't forget to divide by 1.6x10^-19)

Last edited: 21 May 2006
9. Dave

# Location: Sacramento CA

You know E = hf = hc/(lambda) so you can work out the frequency.

The de Broglie wavelength is (lambda) = h / p

So, hc/E = h/p, i.e. p = E/c.

Although being a photon, it's speed is c. You sure its asking to work out speed?

10. MrMatteh

# Location: Essex

it has no m, it's a photon

ah, ninja edit

# Location: London

actually, quite a few A level physics questions will be these sort of trick questions for one or two marks.

Check the question again.

12. MrMatteh

# Location: Essex

trick question?

e=hc/λ

job done.

# Location: London

speed, not energy. thats what he needs to find, apparently.

14. MrMatteh

# Location: Essex

under most circumstances, the speed will be 3x10^8. I can't see that being the question

perhaps its something to do with the photoelectric effect, difficult to tell from the OPs wording

# Location: London

As someone who took A level physics only a year ago, I can attest to the fact that they do have these little trick questions.

hence why I suggested it being one.

16. Visage

# Posts: 10,708

Not quite. The method of creation has no bearing on the nature of the reulstant photon. X-Rays can also be created in inter-stellar collisions, for example, as measured by CHANDRA.

To anser the OP, an X-Ray photon is simply a high energy photon.

17. Visage

# Posts: 10,708

It may be questioning what the recoil velocity is - an atom of mass m emits a photon with energy E, at what speed does the atom recoil....that kind of question.

18. MrMatteh

# Location: Essex

yups

come on OP, tell us the whole question!

19. AthlonTom

# Posts: 1,884

Its a photon isn't it, oh and has anyone seen that X-Ray lazer majig?

20. daz

# Location: Bucks

I know it has no bearing on the resultant photon. However, what we define as X-rays and gamma rays overlap, the only difference being the method of creation.