Niels+Bohr

Niels Bohr [] [|www.kentchemistry.com/links/AtomicStructure/Bohr.htm]

Summarize Bohr’s model of the atom. Compare and contrast his model to Rutherford’s model. What new knowledge did we gain? What was wrong with Rutherford’s model? Did any of Rutherford’s ideas continue to be valid? Summarize Bohr’s concept of electrons absorbing and emitting energy.

Based on the two videos, explain the major flaws of Rutherford’s model of the atom. =According to the video: =

Rutherford

 * An orbiting electron should emit radiation
 * Radiation will change in frequency as the electron looses energy eventually as the electron looses energy
 * Eventually the electron will spiral into the nucleus causing who knows what to happen
 * Don’t change color or blow up disappear or self destruct

Bohr

 * Orbiting electron doesn’t necessarily radiate energy
 * Matter when absorbing radiation discrete bundles of energy, or a quantum
 * Travel in small orbits
 * Electron near the nucleus is attracted strongly
 * <span style="font-family: Georgia,serif;">Conclusion: Around the nucleus of an atom an electron may occupy only certain precise orbits or energy levels
 * <span style="font-family: Georgia,serif;">Prediction: For the hydrogen atom, the radius for the orbits was given by the equation directly related to the orbit number
 * <span style="font-family: Georgia,serif;">Equation for speed of an orbit:
 * <span style="font-family: Georgia,serif;">v=2.18 x 10^6/orbit # = speed in m/s
 * <span style="font-family: Georgia,serif;">Calculating the energy of electron:
 * <span style="font-family: Georgia,serif;">Function of speed of electron and the attraction between nucleus and electron (depends on the distance square between them)
 * <span style="font-family: Georgia,serif;">Predicted the energy levels in each orbit for the hydrogen atoms

=<span style="font-family: Georgia,serif;">Niel Bohr = =<span style="font-family: Georgia,serif;"> =

=<span style="font-family: Georgia,serif;">Planetary Atom = =<span style="font-family: Georgia,serif;"> =

<span style="font-family: Georgia,serif;">This is the planetary atom where it shows how the protons and electrons <span style="font-family: Georgia,serif;">circulate around the nucleus, just like how the planets circulate around the sun. <span style="font-family: Georgia,serif;">thats is why they call it the planetary atom.

=<span style="font-family: Georgia,serif;">Bohr's model of an atom =

<span style="font-family: Georgia,serif;"> <span style="font-family: Georgia,serif;">In Bohr's model of an atom, his model is like a planetary atom. He describes how the atom has negative <span style="font-family: Georgia,serif;">electron that circulate around a positive nucleus.


 * <span style="font-family: Georgia,serif;">Compare and contrast his model to Rutherford’s model. What new knowledge did we gain? What was wrong with Rutherford’s model? Did any of Rutherford’s ideas continue to be valid? **

<span style="font-family: Georgia,serif;">**Answer:** Rutherford stated that the atom had a small, dense core or the nucleus. The nucleus was positively charged (protons) and surrounded by negatively charged particles (electrons). The # of protons and the # of neutrons was equal, thus making each other cancel out forming neutrons meaning neutral. Rutherford and Bohr agreed on this. Much like Bohr's statement, Rutherford also stated that this model resembled the solar system. Bohr helped us gain knowledge that predicted the speed of the electron in each orbit. He concluded that around the nucleus the electrons can only occupy certain orbits or energy levels in the hydrogen atom.

<span style="font-family: Georgia,serif;">Electrons can change their orbit by emission of photons or by absorbtion of photons. <span style="font-family: Georgia,serif;">

The spectrum of the atoms. <span style="font-family: Georgia,serif;">

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