explain neil bohr's theory and dalton's thory

Asked by kanishkapanwar2424 | 2nd Sep, 2014, 05:57: PM

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Solution for your first query,
 Niels Bohr's theory was based on the atomic model proposed earlier by Rutherford. The deduction of the Balmer series for the line spectrum of hydrogen and of the Rydberg number from universal atomic constants constituted its first convincing confirmation.
Bohr suggested that if an electron gained energy it would move into a higher energy orbit., farther from the nucleus. If it lost energy it would slip back into a lower energy orbit, closer to the nucleus. Bohr recognized that the idea of electrons jumping between orbits fit with the idea of light quanta in quantum theory. Perhaps an atom could absorb only photons of certain sizes.
  1. Niels Bohr suggested that electrons in an atom were restricted to specific orbits around the atoms nucleus.
  2. Bohr argued that an electron in a given orbit has a constant energy, thus he named these orbits energy level.
  3. When an electron gains energy, it can use this energy to jump from a lower energy orbit to a higher energy orbit.
  4. When an electron falls from a higher energy orbit to a lower energy orbit it releases energy in the form of light.
  5. White is not a color of light itself, but rather results when light of every other color is mixed together.
  6. In Bohr's model electrons can only exist in certain orbits and thus, can only have certain energies. As a result we say that the energies of the electron are quantized.
  7.  Bohr used the formula En = -Rhe/n to predict the energy level of an electron in the nth energy level of a hydrogen atom.
  8. Because the electron is only allowed to exist at certain energy levels according to the Bohr model, there are only a few possible energies of light which can be released when electrons fall one energy level to another. Asa result the Bohr model explains why atomic spectra are discontinuous.
  9. The Bohr model successfully predicts the four colored lines in hydrogen's atomic spectrum, but it fails miserably when applied to any atom with more than one electron. This is due to the difference between the laws of classical physics and the laws of quantum physics.
  10. The Bohr model is no longer accepted as a valid model of the atom.

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Answered by Prachi Sawant | 4th Sep, 2014, 10:40: AM