Bohr atomic model atom building using

So, which model is correct Is it the Bohr model or the quantum mechanical model Remember that, in science, we build models (or theories) and then perform experiments in an attempt to validate them. The Bohr model has been shown to be invalid by experiments. The quantum mechanical model is consistent with all experiments to date. Of course, this doesn t make the quantum mechanical theory true. Scientific theories are never proven true, only valid. This also does not mean that the Bohr model is not useful. In fact, the Bohr model is sufficient to predict much of the chemical behavior we encoimter in this book. However, the quantum mechanical model gives us a better picture of atoms. 

Lewis appropriated Bohr s new atom to try to unify the physical and chemical atom. If the Bohr-Sommerfeld orbits are in fixed positions and orientations, "they may be used as the building stones of an atom which has an essentially static character." 17 Bohr s dynamic theory works for the chemist, Lewis wrote, if the "average" position of an electron in a Bohr-Sommerfeld orbit is taken to correspond to the fixed position of the electron in Lewis s static chemical model. The outermost shell of electrons constitutes the "valence" electrons, and the remaining electrons constitute the "kernel." 18... 

Bohr realised that, by purely theoretical considerations and the construction of models, the desired object of explaining the regularities in the structures of atoms (periodic system of the elements) would be very difficult to attain he therefore adopted a procedure by means of which, half theoretically and half empirically, making use of all the evidence provided by physics and chemistry, and, especially, by a thorough application of the data derived from the series spectra, there was evolved a picture of the building up of atoms. 

We need to build up a reliable description of atoms because atoms are the building blocks we will use to construct molecules. Chapters 1 and 2 present basic rules of quantum mechanics, using the semi-classical Bohr model and the idealized particle-in-a-box problems as fundamental examples. But the Bohr model is not a three-dimensional model, and our atoms—and the chemical bonds that they form—are three-dimensional. Therefore, we return to the structure of atoms, but now, with the tools of quantum mechanics at our disposal, we will describe them more accurately. 

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