Advertisements
Advertisements
Question
The Bohr radius is given by `a_0 = (∈_0h^2)/{pime^2}`. Verify that the RHS has dimensions of length.
Advertisements
Solution
The dimensions of ε0 can be derived from the formula given below:
`a = (epsilon_0h^2)/(pime^2) = (A^2T^0(ML^2 T^-1)^2)/(L^2ML^-2 (AT)^2)`
`=(M^2L^2T^-2)/(M^2L^3T^-2) = L`
Clearly, a0 has the dimensions of length.
APPEARS IN
RELATED QUESTIONS
What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is –2.18 × 10–11 ergs.
The ratio of kinetic energy of an electron in Bohr’s orbit to its total energy in the same orbit is
(A) – 1
(B) 2
(C) 1/2
(D) – 0.5
In Bohr’s model of the hydrogen atom, the radius of the first orbit of an electron is r0 . Then, the radius of the third orbit is:
a) `r_0/9`
b) `r_0`
c) `3r_0`
d) `9r_0`
if `E_p` and `E_k` represent potential energy and kinetic energy respectively, of an orbital electron, then, according to B9hr's theory:
a)`E_k = -E_p"/"2`
b) `E_k = -E_p`
c) `E_k = -2E_p`
d) `E_k = 2E_p`
State Bohr postulate of hydrogen atom that gives the relationship for the frequency of emitted photon in a transition.
Using Bohr’s postulates, obtain the expression for the total energy of the electron in the stationary states of the hydrogen atom. Hence draw the energy level diagram showing how the line spectra corresponding to Balmer series occur due to transition between energy levels.
The electron in hydrogen atom is initially in the third excited state. What is the maximum number of spectral lines which can be emitted when it finally moves to the ground state?
Find the wavelength of the radiation emitted by hydrogen in the transitions (a) n = 3 to n= 2, (b) n = 5 to n = 4 and (c) n = 10 to n = 9.
Evaluate Rydberg constant by putting the values of the fundamental constants in its expression.
A positive ion having just one electron ejects it if a photon of wavelength 228 Å or less is absorbed by it. Identify the ion.
According to Maxwell's theory of electrodynamics, an electron going in a circle should emit radiation of frequency equal to its frequency of revolution. What should be the wavelength of the radiation emitted by a hydrogen atom in ground state if this rule is followed?
Answer the following question.
Calculate the orbital period of the electron in the first excited state of the hydrogen atom.
When the electron orbiting in hydrogen atom in its ground state moves to the third excited state, show how the de Broglie wavelength associated with it would be affected.
Mention demerits of Bohr’s Atomic model.
The energy associated with the first orbit of He+ is ____________ J.
Ratio of longest to shortest wavelength in Balmer series is ______.
If 13.6 eV energy is required to ionize the hydrogen atom, then the energy required to remove an electron from n = 2 is ______.
The figure below is the Energy level diagram for the Hydrogen atom. Study the transitions shown and answer the following question:
- State the type of spectrum obtained.
- Name the series of spectrum obtained.

What is the velocity of an electron in the 3rd orbit of hydrogen atom if its velocity in the 1st orbit is v0?
