Question

why eletron moving in fixed orbit don't radiate energy? Bohr's atomic model

Answer 1

Good question. I've wanted to know the answer to that from a long time.

Answer 2

@experimentX @ujjwal

Answer 3

honestly i haven't understood this Q well ... myself. first of all why would electron radiate energy? do you know that?

Answer 4

To explain this, lets begin from De-broglie wave particle duality. Electrons revolving in certain fixed orbit act as wave with wavelength given by de-broglie's equation, and amazingly they form stationary wave.. Since energy is not transferred, rather it is confined in a stationary wave, electrons (which act as stationary wave) don't release energy in fixed orbits.

That is what i have understood!
99% of all people answering this would simply state bohr's postulate which is not an answer!

Answer 5

yeah i know that ... but the problem runs much deeper than that.
why would a charged particle radiate energy when revolving around a positive core?

Answer 6

the problem is we know that accelerating charge produces em waves ... and the electron is constantly changing direction. but same phenomenon happens when a moving electron is projected into uniform magnetic field.

Answer 7

I think your latest reply answers the question you posed in the previous reply @experimentX . So, delete the previous reply.

Answer 8

When a moving electron is projected is projected in a uniform magnetic field, it does emit EM radiation! And so instead of following exact circular path electron rather follow spiral path..

Answer 9

huh?? that was supposed to be Q for myself too. trying to work on these things.

Answer 10

Easy squeezy answer!

Answer 11

They don't do that until you apply supply some amount of energy to them so that the electrons jump to a higher shell,where is the exact confusion?

Answer 12

OK, but you should make your present View (or idea) more clear so that we can understand what you're thinking. @experimentX

Answer 13

What the heaven just happened? A bug!

Answer 14

@experimentX "why would a charged particle radiate energy when revolving around a positive core?"
Who told you that?

Answer 15

http://wiki.answers.com/Q/What_is_the_drawback_of_rutherford's_model_of_an_atom

Answer 16

that's the key point for failure of Rutherford model .... i;ve been reading that point since 11 th grade. still not being able to figure it out.

Answer 17

What exactly are you not being able to figure out?

Answer 18

the right combinations of equations to explain these stuff.

Answer 19

The original question remains unanswered, @ujjwal.

Answer 20

I answered it in my first post @rajathsbhat

Answer 21

the original Q is actually answered ... but there are lots of things between them are missing ... which i would like to know.

Answer 22

@experimentX dont collect the remnant pieces of newtons equation!
that law is only for macroscopic bodies! not microscopic!

Answer 23

the Rutherford model failed from classic model ... and Newton did not formulate the EM equations.

Answer 24

I'd tell you,later it was found that the fault was in newton's theory,not rutherford,he was right on his part..but they proved that the law was only for macroscopic particles not microscopic ones like electrons..so

Answer 25

But it ain't clear to me! Yes the original Q has been answered somewhat, but not so clearly that it clears all our doubts.

Answer 26

Maxwell said that "charged particle radiate energy when revolving around a positive core"

Answer 27

Sorry why am i saying newton lol
kinda sleepy!

Answer 28

I told you ... this should be done much from Maxwell's Equation less from Newtonian mechanics ... and explained from introduction of QM.

Answer 29

Right,i apologize,but the solution was correct

Answer 30

I agree, @experimentX .

Answer 31

I know about Bremsstrahlung.. I know a bit! I know that an accelerating charged particle radiates energy. But i don't know precisely "why?".. And i have read that a charged particle accelerating under the effect of gravity doesn't emit radiation! Amazing! Have you got any idea @experimentX ?

Answer 32

To attain stability

Answer 33

What kind of stability?

Answer 34

If you are talking in terms of electrons,to achieve stability

Answer 35

yea ... the explanation is correct ... the radius (path around) of the electron around nucleus must be equal to the integer multiple of de-Broglie wavelength (or half-wavelength i forgot) ...so that it can form stationary wave.

Answer 36

that gives Neil bhor's model.

Answer 37

ok, the qsn now is "why would an accelerating charged particle emit photon?"

And i don't get it when DLS simply says "stability".. Can anyone explain?

Answer 38

I don't think it emits photons. I think it produces EM waves..

Answer 39

light does not have mass but has momentum ... and this particle side of light is called photon. whatever ... probably same.

Answer 40

In classical theory, accelerated charged particle does not radiate photons. It radiates electromagnetic waves of E, B, which will manifest themselves by altering the motion of the surrounding particles.

Answer 41

What makes you guys think that electromagnetic wave and photons are two entirely different things??

Answer 42

this is because classically light is not a particle ...

Answer 43

Electromagnetic wave=Electric field+magnetic field i.e two components
photon is just a particle not a wave so it wont have those two comps.

Answer 44

Ok, so, when i say an accelerating charged particle emits photons, am i wrong? I don't think so..

Answer 45

It emits radiations..electromagnetic wali!

Answer 46

http://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality

Answer 47

where did that come from now

Answer 48

But photons=only visible light. Not IR, not UV...nothing else.

Answer 49

photons are not necessarily 'visible' ones..

Answer 50

dont confuse
photon,when we talk is a particle
light as a whole is a wave

Answer 51

Everything has wavelength associated with them ... why don't you think gamma rays would produce photoelectric effect?

Answer 52

Yea. OK. I rest my case.

Answer 53

if you move any object with high velocity ... it behaves as wave.

Answer 54

That.

Answer 55

"if you move any object with high velocity ... it behaves as wave"
Right,
Consider electron as an object
Its mass is like 9.1 * 10^-31,it is so negligible..isn't it?
Now,
\[\lambda = h/mv\]
=>Inversely proportional to mass
So lamda would be high right? since the mass is so small..

When talking of bodies,like 0.1kg lambda would be very low! so they wont show the wave like properties even though if they posses them..

Answer 56

This law is restricted to microscopic particles,so you cant just say any object

Answer 57

That applies even to you when you are running @DLS

Answer 58

What are you trying to say?

Answer 59

De-broglie equation is valid for every single particle...

Answer 60

Read again
When talking of bodies,like 0.1kg lambda would be very low! so they wont show the wave like properties even though if they posses them

Answer 61

yep ... i heard it from my teacher that i applies ... but since your velocity is is so slow .... you would have more particle nature and less wave nature.