# According to Bohr's model of an atom, which of the following is/are quantized? (a) The total energy of electron is quantized. (b) Angular momentum of electron is quantized. (c) both (a) and (b). (d) None of the above.

##### 1 Answer

Both **energy** and **angular momentum** are *observables* that correspond to so-called *eigenvalues*. Eigenvalues are the values that describe a result that occurs consistently, brought about by an observation.

All energies **quantum number**.

An example of **atomic energies** is the hydrogen atom in the Rydberg equation:

#DeltaE = -"13.6 eV"(1/n_f^2 - 1/n_i^2)# where:

#n_i# and#n_f# are the initial and final quantum numbers#n# for the energy levels across which an energy transition occurs.#DeltaE# is the energy gap for that transition in units of#"eV"# (#1.602 xx 10^(-19)# #"J"# #=# #"1 eV"# ).

#n = 1, 2, 3, . . .# is the principal quantum number, indicating each energy level, corresponding to eigenvalues#E_n# .Since

#n# is, it goes in integer steps, and thus the energy is quantized as well.quantized

The **angular momentum** of the electron, corresponding to the "shape" of an orbital (not necessarily a thing for Bohr's model, which pretends there are orbits instead), has eigenvalues dependent on the quantum number,

#l = 0, 1, 2, . . . , n-1# is the angular momentum quantum number, corresponding to the eigenvalue#l(l+1)ℏ^2# of the squared angular momentum,#L^2# .

Clearly,

What about