Why does Bohr's model of the atom violate the Heisenberg Uncertainty Principle?

1 Answer
Jan 13, 2018

Well, Bohr's model of the atom assumes fixed orbits AND trajectories for the electron. Simultaneously known orbits and trajectories violate the Heisenberg Uncertainty Principle.


Bohr's model of the nitrogen atom is:

https://media1.britannica.com/

The problem is, electrons do NOT travel in fixed orbits, and they do NOT travel with fixed trajectories. That is, they should NOT have simultaneously well-known positions #x# and momenta #p_x#.

Therefore, it should NOT be that the uncertainties in position and momentum are #Deltax = Deltap_x = 0#.

Heisenberg's Uncertainty Principle is:

#DeltaxDeltap_x >= ℏ//2#

The constant #ℏ = h//2pi# is the reduced Planck's constant, where #h = 6.626 xx 10^(-34) "J"cdot"s"#.

If #DeltaxDeltap_x = 0#, it cannot be greater than or equal to #ℏ//2#.

Therefore, the uncertainty #Deltax# in position, and the uncertainty #Deltap_x# in momentum, cannot both be zero...