How did the work of De Broglie... (1 Viewer)

[sctr]

Could someone please answer this question:

Explain what the 'wave - particle' duality is. How did the work of de Broglie complete the work of Einstein and Planck in this respect?

this would be greating appreciated if you peeoples could help me out


-sctr

 

[insert-username]

Wave-particle duality holds that light and matter exhibit properties of both waves and of particles. de Broglie took Einstein's E = mc² and Planck's E = hf and equated them together to find an expression relating wavelength, frequency, and momentum. The de Broglie hypothesis stated that all matter has a wave-like nature, and this extended on Planck and Einstein's theories on the particle nature of light to cover all matter as well.


I_F

 

[sctr]

thanks dude

can anyone else add on to this/

 

[del pietro]

yeh basically he proved that electrons could act as waves by equating planks and einstines equations as 'insert-username' mentions.. de broglie represented electrons as standing waves. As an electron absorbed energy in a specific amount (quantum) they could move into higher energy standing wave levels. similarily they could move to lower energy elvels by releasing this energy in specific ammounts, as photons..

 

[alcalder]

Actually, de Broglie proposed that electrons were both particles and waves. He thought that if light were a wave that exhibited particle properties, perhaps these two were linked and for neatness he proposed that particles also exhibited wave properties. Thus, an electron, being a particle, could also have wave properties. Yet, for there to be electrons in an orbit, there would need to be an integer number of wavelengths in an "orbit" - similar to standing waves.

He completed Einstein and Planck's work because he used their formulae to come up with this proposal.

E= mc² E=hf

mc² = hf

He stated that c = v of the particle and we know f = v/λ

mv² = hv/λ

mv = h/λ

λ = h/(mv) - the de Broglie wavelength

He proposed that an electron would have a wavelength so small that diffraction of electron waves would be detectable when bombarding crystals with electrons. He did not observe it, nor did he prove it.

His work was dismissed until Einstein had a look at it and commented: "I believe it is a first feeble ray of light on this worst of our physics engimas."

It was actually first a young man called Walthar Elessar (a student of Max Born in 1923) who first explained the strange behaviour of electron scattering from the surface of crystals in terms of de Broglie's proposal (an experiment conducted by Davisson and Charles Kunsman in 1922/23)). Elessar's explanation was not appreciated or accepted.

Then in 1927, Davisson and Germer, when scattering electrons from nickel had a fortunate accident and thus ended up scattering electrons from Nickel crystals and observed a diffration pattern similar to that of X-Ray diffraction (known waves). It was then that electrons were proven to be waves as well as particles.

Actually, it's also ironic that, at the same time as Germer and Davisson, G.P Thomson (JJ Thomson's son) proved the same thing when scattering electrons from thin gold foils. JJ Thomson proved the electron was a particle, his son proved it was a wave!

Another interesting result. Using his mathematics, he was able to show the angular momentum of such an electron wave/particle was identical to that calculated by Bohr.