Help with Quantized energy

Hi, I have been working on this question for some time and can't put my finger on the answer.

Q: What experimental evidence requires that the emission of energy by an atom be quantized?

Now we have just been studying the evolution of the atomic theroy. I think it has to do with the work by Max Planck but in the text it talks about his experiment with incandescent bodies (which is where the topic first comes in) but gives no specific evidence as to why the energy would be quantized.

I also thought it may be the atomic emission spectra as shown with the prism experiment - but I dont see how this evidence relates to the energy being quantized.

Any help would be welcome.



Comment viewing options


1 nanometer ( nm ) = 10 to

1 nanometer ( nm ) = 10 to the -9 meters

1 Angstron ( A ) = 10 to the -10 meters

h = Plancks Constant = 6.625 times 10 to the -27 ers - seconds

f = hertz = frequency ( HZ )

lambda = wavelength at room temperature, at one atmosphere

f = 1 / lambda

E = 1.24 nanometers / lambda

E = H F

frequency is cycles per

frequency is cycles per second

joules is the amount of energy or enthalpy per mole

there is a variable missing in your calculation .

that variable is the conversion factor between amount of energy

and cycles per second to go from energy to frequency

Einstein won a Nobel prize

Einstein won a Nobel prize for pointing out the evidence that demands quantized energy. Check his bio.

the spectra are composed of discrete lines: particular freqencies.
Why do you think that is?

I understand that the colours represent different frequencies. That when refracted they separate based on the wavelength of the light. Different elements give off unique spectascope signatures... but I am not sure how that ties into the energy being quantized.

Perhaps I am having trouble with the definition of quantized energy. Quanta are the packets of radient energy emitted.
The quantum of enery is ....value, amount of energy?
and quantized energy is the actual wavelength?

Am I on the right track?

yeah well someone decided that the frequency of light (f, measured in hertz) was directly proportional to the amount of energy (E, measured in joules) that each photon has:

E = hf

(the "h" is Plank's constant. So maybe it was him dreamt this up. :)

You getting any closer yet...?

The quantisation idea first came about when plank was trying to explain the emission spectrum of black body radiation, so just google black body radiation and you should find out what you need.

here's a pdf on black body radiation, the more you get into it, the more mathamatical it gets.


Ok Back to this

Ok Back to this problem...
The evidence I am looking for is that when energy is radiated, it is only radiated in certain energy values - as seen in the black body experiments and his experimaents with incandescent bodies.
This is also seen as each element has its own atomic emission.

Am I on the right track now?

Thanks for all you help.....

WebElements: the periodic table on the WWW []
