Lesson #15 Bohr's atomic theory

in #chemistry7 years ago

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Bohr's atomic theory:

In 1913 neil bohr, proposed a model for an atom that was consistent with Rutherford model. But it also explains the abserved line spectrum of the hydrogen atom.

Main postulates of bohr atomic theory:

  1. The electron in an atom revolves around the nucleus in one of the circular orbit. Each orbit has a fixed energy. So each orbit is also called energy level.
  2. The energy of the electron in an orbit is proportional to its distance from the nucleus. The further the electron is from the nucleus,the more energy it has.
  3. The electron revolves only in those orbits for which angular momentum of the electron in an integral multiple of h/2×3.14
    h:
    H is planks constant its value is 6.626×10 power -10 j.s.
  4. Light is obsorbed when an electron jumps to a higher energy orbit and emitted when electron jumps to a lower energy orbit. Electron present in a particular orbit does not radiate enrgy.
  5. The energy of the light emitted is exactly equal to the difference between the energies of the orbit.