Hydrogen atoms Bohr model

Although currently (as a matter of fact even since its publication by Heisenberg in 1927) are heated discussions and attempts to dismantle the dogma imposed by limiting/Heisenberg uncertainty in the Planck constant, the utility of this relationship (even borderline) is incontestable, which will be illustrated also by application to the Hydrogen atom (Bohr model), immediately below, and latter in a more elaborate framework. 

Scientists of the nineteenth century lacked the concepts necessary to explain line spectra. Even in the first decade of the twentieth century, a suitable explanation proved elusive. This changed in 1913 when Niels Bohr, a Danish physicist and student of Rutherford, proposed a new model for the hydrogen atom. This model retained some of the features of Rutherford s model. More importantly, it was able to explain the line spectrum for hydrogen because it incorporated several new ideas about energy. As you can see in Figure 3.8, Bohr s atomic model pictures electrons in orbit around a central nucleus. Unlike Rutherford s model, however, in which electrons may move anywhere within the volume of space around the nucleus, Bohr s model imposes certain restrictions. 

In 1913 a Danish physicist named Niels Bohr, aware of most of the experimental results we have just discussed, developed a quantum model for the hydrogen atom. Bohr proposed a model that included the idea that the electron in a hydrogen atom moves around the nucleus only in certain allowed... 

The Bohr model of the hydrogen atom postulated that the electron moved in circular orbits corresponding to the various allowed energy levels. Though it worked well for hydrogen, the Bohr model did not work for other atoms. 

Bohr first proposed an electron motion model to solve the problems of the Rutherford model. For the electron in a hydrogen atom, Bohr presented an atomistic model, in which the periodic orbits of electrons are quantized, and proposed the following hypothesis, known as the Bohr hypothesis (Bohr 1913) ... 

To explain the Rydberg equation, Eq. 1.5, Niels Bohr proposed the model of the atom pictured in Fig. 1.11. This was an irresistibly simple proposal that answered the fundamental question raised by the Rydberg equation what determines the energy levels of the hydrogen atom The model would turn out to be valuable, but imperfect. It was viewed with some suspicion from the beginning, for it rested on unfounded—and apparently unjustifiable—assumptions. 

The hydrogen atom, containing a single electron, has played a major role in the development of models of electronic structure. In 1913 Niels Bohr (1885-1962), a Danish physicist, offered a theoretical explanation of the atomic spectrum of hydrogen. His model was based largely on classical mechanics. In 1922 this model earned him the Nobel Prize in physics. By that time, Bohr had become director of the Institute of Theoretical Physics at Copenhagen. There he helped develop the new discipline of quantum mechanics, used by other scientists to construct a more sophisticated model for the hydrogen atom. 

The last equation written is the one Bohr derived in applying his model to the hydrogen atom. Given... 

At this point a Danish physicist, Niels Bohr, decided to take a fresh start. In effect, he faced the fact that an explanation is a search for likenesses between a system under study and a well-understood model system. An explanation is not good unless the likenesses are strong. Niels Bohr suggested that the mechanical and electrical behavior of macroscopic bodies is not a completely suitable model for the hydrogen atom. He pro-... 

In an early model of the hydrogen atom proposed by Niels Bohr, the electron traveled in a circular orbit of radius uncertainty principle rules out this model. 

Using Bohr s model, one could calculate the energy difference between orbits of an electron in a hydrogen atom with Planck s equation. In the example of a system with only two possible orbits, the equation of the emitted radiation as the electron went from a higher energy state 2 to a lower one j would be - E = hf, where h is Planck s constant and/is the frequency of the emitted radiation. 

The Bohr atom went a long way toward explaining the nature of atoms, but there were problems. Although scientists could calculate the emission spectrum of hydrogen using the Bohr model, the model could not account for the spectra of heavier atoms. The biggest problem with the Bohr atom, however, lay in its lack of a... 

This assumption is the basis of the Bohr model for the hydrogen-like atom. When solved for m, this balancing equation is... 

Following Rutherford s experiments in 1911, Niels Bohr proposed in 1913 a dynamic model of the hydrogen atom that was based on certain assumptions. The first of these assumptions was that there were certain "allowed" orbits in which the electron could move without radiating electromagnetic energy. Further, these were orbits in which the angular momentum of the electron (which for a rotating object is expressed as mvr) is a multiple of h/2ir (which is also written as fi),... 

Bohr s model of the hydrogen atom. Identification of atomic number with nuclear charge number (H. Moseley). 

Bohr s hydrogen atom model of 1913 had provided inspiration to a few physicists, like Kossel, who were interested in chemical problems but to very few chemists concerned with the explanation of valence. First of all, the Bohr atom had a dynamic character that was not consistent with the static and stable characteristics of ordinary molecules. Second, Bohr s approach, as amended by Kossel, could not even account for the fundamental tetrahedral structure of organic molecules because it was based on a planar atomic model. Nor could it account for "homopolar" or covalent bonds, because the radii of the Bohr orbits were calculated on the basis of a Coulombic force model. Although Bohr discussed H2, HC1, H20, and CH4, physicists and physical chemists mainly took up the problem of H2, which seemed most amenable to further treatment. 11... 

---