List of top Physics Questions on Atoms

Prove that, in the Bohr model of the hydrogen atom, the time period of revolution of an electron in the \( n \)-th orbit is proportional to \( n^3 \).
Assertion (A): The potential energy of an electron revolving in any stationary orbit in a hydrogen atom is positive.
Reason (R): The total energy of a charged particle is always positive.
The distance of closest approach of an alpha particle from a nucleus when the alpha particle moves towards a nucleus with a kinetic energy 'E' is 'x'. The distance of closest approach when the alpha particle approaches the same nucleus with kinetic energy 0.4E is
The ratio of frequencies of second line of Lyman series and third line of Balmer series of hydrogen atom is:
The ratio of wavelengths of second line in Balmer series and the first line in Lyman series of hydrogen atom is
Describe the atomic model of Rutherford. How did Bohr model removed its drawbacks?
Describe in brief, the \(\alpha\)-scattering experiment. Write down about the atomic-structure from the observation obtained from the experiment.
What are the demerits of Rutherford model of an atom ?
The ratio of the shortest wavelength of Balmer series to the shortest wavelength of Lyman series for hydrogen atom is :
In hydrogen like system the ratio of coulombian force and gravitational force between an electron and a proton is in the order of:
A hydrogen atom in ground state is given an energy of 10.2 eV. How many spectral lines will be emitted due to transition of electrons ?
If the wavelength of the first member of the Lyman series of hydrogen is \( \lambda \). The wavelength of the second member will be:
The radius of the third stationary orbit of an electron in Bohr's atom is \( R \). The radius of the fourth stationary orbit will be:
If Rydberg’s constant is \( R \), the longest wavelength of radiation in Paschen series will be \( \frac{\alpha}{7R} \), where \( \alpha = \_\_\_\_\_\_\_ \).
The spectral series which corresponds to the electronic transition from the levels n2 = 5, 6,… to the level n1 = 4 is
(a) "EM wavelength correlates with the size of the radiating system." Give two examples.
(i) Why do long-distance radio broadcasts use shortwave bands?
(ii) Why are X-ray telescopes satellite-based, while optical/radio telescopes are ground-based?
In the Balmer series of the hydrogen atom, as the wavelength of spectral lines decreases, they appear:
The radius \( r_n \) of the \( n^{th} \) orbit in the Bohr model of the hydrogen atom varies with \( n \) as:

In Bohr model of hydrogen atom, if the difference between the radii of \( n^{th} \) and\( (n+1)^{th} \)orbits is equal to the radius of the \( (n-1)^{th} \) orbit, then the value of \( n \) is:

In a common emitter transistor circuit, if the emitter current is changed by 4 mA, the collector current changes by 3.5 mA, then the current gain is
In Bohr model of hydrogen atom, if the difference between the radii of \( n^{th} \) and \( (n+1)^{th} \) orbits is equal to the radius of the \( (n-1)^{th} \) orbit, then the value of \( n \) is:

The radius of innermost orbit of a hydrogen atom is 5.3x10-11 m. What is the radius of the third allowed orbit of the hydrogen atom?

Draw the energy level diagram for hydrogen atom. Show the transitions of Lyman, Balmer, Paschen, Brackett and Pfund series in the diagram. In which region do these spectrum lie?

If the two metals $A$ and $B$ are exposed to radiation of wavelength $350 mm$. The work functions of metals $A$ and $B$ are $4.8 eV$ and $2.2 eV$. Then choose the correct option

The energy levels of an hydrogen atom are shown below. The transition corresponding to emission of shortest wavelength is
energy level