After the Rutherford experiment, which established a planetary model for the atom, a problem existed as to why electrons stay in orbit. Electromagnetic Theory would predict that the electron would spiral in to the nucleus.
Clearly this does not happen (we would not be here to learn about it!)
Niels Bohr, in 1913, introduced quantum understanding to solve this problem. But before we look at Bohr's solution, we also need to examine another discovery that helped Bohr develop his model.
Clearly this does not happen (we would not be here to learn about it!)
Niels Bohr, in 1913, introduced quantum understanding to solve this problem. But before we look at Bohr's solution, we also need to examine another discovery that helped Bohr develop his model.
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In the late 1800's spectroscopy and spectral analysis had come some way after the initial discoveries of spectral lines by the German physicist, Joseph von Fraunhofer. However, was there a pattern to the produced lines? There was, and that work was done by Swedish physicist Johannes Rydberg and later, Johann Balmer, the mathematician from Switzerland. Watch this video to find out more. |
Sample Problem
We are now ready to try a sample problem
Below is a sample problem with a video that explain how to solve it. It is suggested you try the problem beforehand, as this actually aids understanding, even if you are unsure if you are correct.
We are now ready to try a sample problem
Below is a sample problem with a video that explain how to solve it. It is suggested you try the problem beforehand, as this actually aids understanding, even if you are unsure if you are correct.
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An emission spectrum of hydrogen reveals four lines in the visible range, called the Balmer Series. What frequency of light is emitted if the electron transition associated with this frequency moves from 5 to 2? |
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Theory
We have now covered the groundwork that Bohr examines - the baviour of atomic spectra, the mathematical models of Balmer, the flaws in the Rutherford model, and now, the hypothesis from Planck, that energy can be quantised
It is from here that Bohr set out to develop a atomic that had quanta as is basis (though not completely as you shall see)
We have now covered the groundwork that Bohr examines - the baviour of atomic spectra, the mathematical models of Balmer, the flaws in the Rutherford model, and now, the hypothesis from Planck, that energy can be quantised
It is from here that Bohr set out to develop a atomic that had quanta as is basis (though not completely as you shall see)
Interactive
From Walter Fendt - self explanatory. It does mention de Broglie , which is in the next lesson
From Walter Fendt - self explanatory. It does mention de Broglie , which is in the next lesson
