Bohr+Model

Done by: Anne Smolko Ellen Varner Kaitlyn Kohr

The Bohr model shows the atom as a small, positively charged nucleus that is surrounded by electrons that circle in an orbital around the nucleus.



Bohr Model:

The Bohr model was formulated by Niels Bohr in 1913. While this model is not entirely accurate in its depiction of the atomic structure, it simplifies many of the features of the theory of quantum mechanics, making it much easier to understand. The Bohr model is also often referred to as the “planetary model” of the atom; the neutrons and protons reside within the dense, central nucleus, and the electrons orbit around the nucleus just as the planets orbit the sun.



Differing from the planetary model, however, the energy levels of the particles in the Bohr model are restricted to certain discrete values (quantized energy). That is to say that only those orbits with specific radii can exist. Quantized energy levels can be measured in terms of “n” (the quantum number); the lowest of these energy levels is known as the ground state. As the levels progressively gain more energy, they are said to have entered the first excited state, the second excited state, etc.

Atoms can also make transitions between these orbits by absorbing energy, atomic excitation, or emitting energy, atomic de-excitation, the exact energy difference between the orbits. This energy can be found be using this equation:

E = hc/λ

Energy = (Planck’s constant * Speed of Light) / (Wavelength of the Light)



http://csep10.phys.utk.edu/astr162/lect/light/bohr.html http://education.jlab.org/qa/atom_model_03.gif http://capefeare.com/furious32.jpg http://www.lucidcafe.com/library/95oct/95octgifs/bohr.gif