Physics; Need help please

[xox]

OK, so I have this question on my Physics paper on Line Spectra:

 

 

(a)  Line Spectra were observed before they could be explained by theory. We now know that photons of characteristic frequency are emitted when the vapour of an element is bombarded by energetic electrons. The Spectrum of the light emitted contains lines, each of a definite wavelength.

Explain how:

• The bombarding of electrons cause the atoms of the vapour to emit photons
• The existance of a spectrum consisting of lines of a definite frequency supports the view that atoms have discrete energy levels

[6 marks]

Does anyone know what it is on about? And what kind of stuff would the answer contain? I don't want you to answer the question for me.

 

Thanks, Tom

[Altecice]

The bombardment of electrons causing atoms to emit photons i am sure is just the fact that you change the makeup of the molecule and the light given off is just excess energy.

 

Err as for the lines in the spectrum, I am sure somebody can explain this better but each chemical element has the ability, that it absorbs some light that is shined onto it and those lines in the spectrum are the frequency of the light absorbed meaning we can tell what element something is by applying light to it and listing where the lines are and from that we can deduce what element it is as no two elements absorb the same light.

 

we use it in astronomy quite a bit for finding atmospheres of other planets and our sun for instance:

http://www.extremetech.com/wp-content/uploads/2013/10/sun.jpg

 

the lines show that a certain element is within the sun. relatively new stars would have lots of hydrogen present so it would be more prominent than our middle aged sun.

[xox]

The bombardment of electrons causing atoms to emit photons i am sure is just the fact that you change the makeup of the molecule and the light given off is just excess energy.

 

Err as for the lines in the spectrum, I am sure somebody can explain this better but each chemical element has the ability, that it absorbs some light that is shined onto it and those lines in the spectrum are the frequency of the light absorbed meaning we can tell what element something is by applying light to it and listing where the lines are and from that we can deduce what element it is as no two elements absorb the same light.

 

we use it in astronomy quite a bit for finding atmospheres of other planets and our sun for instance:

http://www.extremetech.com/wp-content/uploads/2013/10/sun.jpg

 

the lines show that a certain element is within the sun. relatively new stars would have lots of hydrogen present so it would be more prominent than our middle aged sun.

Thanks; I've answered it now

 

I think it was about the way that fluorescent bulbs work and electron energy levels.

[Willson94]

[removed]
can i delete my posts? i dont think i can and ive been on this forum a while lol