List of top Physics Questions on Atoms asked in CBSE CLASS XII

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.

(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: