CBSE Class 12 · 2017 · Delhi · Modern PhysicsShort Answer

WhatsApp Email
Write two important limitations of the Rutherford nuclear model of the atom.

Answer: Cannot explain
(i) atomic stability,
(ii) discrete line spectra.

Solution

(i) Stability: according to electromagnetic theory an accelerating (orbiting) electron must continuously radiate energy, spiral inward and fall into the nucleus — so the model cannot explain the stability of atoms.
(ii) Spectra: as the electron spirals in, its frequency of revolution would change continuously, so it should emit a continuous spectrum, whereas atoms actually emit sharp, discrete line spectra.

CBSE Class 12 Board · 2017 · Delhi · Subjective

More board questions on Modern Physics

  1. The potential energy between two nucleons inside a nucleus is minimum at a distance of about
    CBSE 2024View solution →
  2. The variation of the stopping potential with the frequency of the incident radiation for four metals A, B, C and D is shown in the figure. For the same frequency of incident radiation producing photo-electrons in all metals, the kinetic energy of photo-electrons will …
    CBSE 2024View solution →
  3. The energy of an electron in the ground state of a hydrogen atom is eV. The kinetic and potential energy of the electron in the first excited state will be
    CBSE 2024View solution →
  4. Assertion (A): An alpha particle is moving towards a gold nucleus. The impact parameter is maximum for the scattering angle of .
    Reason (R): The impact parameter in an alpha particle scattering experiment does not depend upon the atomic number of the target nucleus.
    CBSE 2024View solution →
  5. Calculate the energy released / absorbed (in MeV) in the nuclear reaction . Given , , …
    CBSE 2024View solution →
  6. A proton of energy 1.6 MeV approaches a gold nucleus . Find the distance of its closest approach.
    CBSE 2024View solution →