How are energy levels and De-Broglie wavelengths related in the Bohr model?

  • A
  • Thread starter blackdranzer
  • Start date
In summary, according to the Bohr/De Broglie postulate, the De-Broglie wavelength of an electron is related to its energy by the equation n λ = 2πr, where λ is the wavelength, r is the radius corresponding to the quantum number n, and n is the quantum number. This means that as the energy of an electron increases, its corresponding De-Broglie wavelength also increases. This is the opposite of what was previously assumed, where energy was thought to decrease as wavelength decreased. However, this postulate is outdated and a more accurate understanding of the behavior of wavelengths for different quantum numbers requires transforming the wavefunction into momentum space. In the hydrogen atom, the ground state (n
  • #1
blackdranzer
6
0
From the Bohr/De Broglie postulate we have n λ = 2πr where λ is the De-Broglie wavelength , r is the radius corresponding to n and n is the quantum number.

  1. An electron in the state n=2 has more energy than that at n=1
  2. That implies that the De- Broglie wavelength associated with the electron should also decrease ?
From the postulate..it is the other way i.e. the wavelength increases as the electron gains energy. How is this possible?.( I had assumed that wavelength decreases with energy)

if we calculate the De-Broglie wavelengths from the postulate:

for n=1 ; λ = 33 * 10^-11 m

for n=2 ; λ = 66 * 10^-11 m

does this mean that as the energy of the electron increases the corresponding De-Broglie wavelength increases?! may be i am missing something very basic here.

semiclassical
 
Physics news on Phys.org
  • #3
blackdranzer said:
does this mean that as the energy of the electron increases the corresponding De-Broglie wavelength increases?! may be i am missing something very basic here.

Bohr's condition, that the angular momentum is an integer multiple of h/2.pi was later reinterpreted in 1924 by de Broglie as a standing wave condition: the electron is described by a wave and a whole number of wavelengths must fit along the circumference of the electron's orbit:

however the atom model is bound state model and in each orbit the particles total energy must be negative (sum of KE + PE) and the lowest orbit is the deepest and slowly it goes towards zero ...i.e. the particle becomes free.
say for hydrogen atom the ionization energy is 13.6 ev .
so the ground state n=1 is at -13.6 eV. so higher states will be closer to zero and the number will be smaller...
so how one can see it ...
say -13.6 eV is larger or smaller than -10 eV ?
one has to supply +3.6 eV to the electron to raise it to -10 eV.
and if an emission has taken place by transfer of electron from say E2 to E1 then E2 - E1 =h.frequencyAn electron in the lowest energy level of hydrogen (n = 1) therefore has about 13.6 eV less energy than a motionless electron infinitely far from the nucleus. The next energy level (n = 2) is −3.4 eV. The third (n = 3) is −1.51 eV, and so on. For larger values of n, these are also the binding energies of a highly excited atom with one electron in a large circular orbit around the rest of the atom.
see wikipedia <https://en.wikipedia.org/wiki/Bohr_model#Origin> for detail discussion
 

What is the Bohr/De-Broglie postulate?

The Bohr/De-Broglie postulate is a principle in quantum mechanics that states that all particles, including electrons, have both wave-like and particle-like properties. It was proposed by Niels Bohr and Louis de Broglie in the early 20th century.

How does the Bohr/De-Broglie postulate relate to the structure of atoms?

The Bohr/De-Broglie postulate explains the structure of atoms by suggesting that electrons orbit the nucleus in specific energy levels, or shells, similar to how waves of light are quantized into discrete energy packets. This postulate helps to explain the stability of atoms and the emission and absorption of energy by electrons.

What evidence supports the Bohr/De-Broglie postulate?

Experimental evidence, such as the diffraction of electrons and the observation of atomic spectra, supports the Bohr/De-Broglie postulate. These phenomena can only be explained by the dual wave-particle nature of electrons proposed by this postulate.

What are the implications of the Bohr/De-Broglie postulate?

The Bohr/De-Broglie postulate has many implications for our understanding of the microscopic world. It helped to establish the field of quantum mechanics and has been essential in the development of technologies such as lasers and transistors. Additionally, it challenges our classical understanding of the behavior of particles and forces us to rethink our perception of reality.

Are there any limitations to the Bohr/De-Broglie postulate?

While the Bohr/De-Broglie postulate has been successful in explaining many phenomena, it is not able to fully explain all aspects of quantum mechanics. For example, it cannot fully explain the behavior of particles at very small scales, such as in the case of the Heisenberg uncertainty principle. Additionally, it does not provide a complete understanding of the nature of particles and their interactions.

Similar threads

Replies
7
Views
852
  • Other Physics Topics
Replies
5
Views
834
Replies
1
Views
980
  • Quantum Interpretations and Foundations
Replies
2
Views
1K
  • Quantum Physics
Replies
8
Views
1K
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Quantum Interpretations and Foundations
Replies
6
Views
2K
Replies
5
Views
1K
  • Classical Physics
Replies
5
Views
943
Back
Top