Monday, August 31, 2009

The Atomic Models

Here are my thoughts on the atomic models.

Chemistry is the study of matter and the changes it undergoes. Since all matter consists of atoms, it is important to understand the atom and its components, in particular of the electron.

Why electrons? Since the electron configuration determines how an element behaves in chemical bonds and chemical reactions. So, if you understand the electron will make you a better understanding of chemistry.

However, you must note that the atom and its components are so small that scientists are not able to work directly with the atom. Therefore, chemists and physicists, models need to help create a description of the atom. But a scientific model is to provide information available when it is created, limited. Thus, if new experiences may lead to new discoveries, the model must be modified or scrapped.

Change Despite the fact that the scientists describe models, the models, the only way of man, as the work of many natural phenomena. And knowing how a process is often crucial for the further scientific discovery. The best estimates of Man, then, the models are not the truth, the models are, how things work. For this reason, the importance of models is not the truth, but their maneuverability.

Keep in mind that the models created by the people and may have prejudices, errors and inaccuracies. Remember always to be models in the light of the scientific method and willing to discard what is not measured.

Even if the models are not perfect, there are five models of the atom, for the understanding of matter. The more these models, you will be better chemistry. The five models are:

* The solid sphere model
* The Plum Pudding Model
* The core model
* The Bohr model
* The Wave Mechanical Model

Solid sphere model

The solid sphere model was proposed in 1803 by John Dalton. John Dalton was a chemistry teacher in English and mathematics, that the ideas have taken his time and in a model of how the matter instead. He said that the material made of tiny indivisible particles as atoms and atoms of the same element are all equal. They also include the law of multiple proportions and the law of definite in his model. Although the model was not perfect, it was the most important primary model for over 90 years.

Plum Pudding

Proposed in 1897 the English physicist JJ Thomson, that cathode rays consist of negatively charged particles even smaller than atoms. In fact, he suggested, these subatomic particles are parts of the atom. Thus, Dalton's theory of indivisible particles was no longer profitable. A new theory, which was not allowed for subatomic particles is required.

Thus, Thomson suggested that the atom had set a mass of positive charge with negative electrons in it, like raisins in a pudding, and that the plum pudding model. Thomson's model, though attractive, but had many shortcomings.

Nuclear Type

In 1906, Ernest Rutherford and his colleagues conducted the famous gold foil experiment, led to the discovery of the nucleus and the atom is mostly space.

Experience has shown that the gold leaf of the mass of the atom are the same as was predicted by the model of Thompson, but the volume of the crowd was much smaller and seemed to not be located in the center of the atom. Thomson's plum pudding model was no longer viable. Thus, in 1911, Rutherford proposed the nuclear model of the atom.

The Bohr model

In 1913 the Danish physicist Niels Bohr, has proposed that the application of quantum theory, the Rutherford model. New model proposed by Bohr, to eliminate the electron energy levels he called orbits. The energy of these orbits is quantized, and must include the electron energy to move or exempt (photons) at specified wavelengths between energy levels.

The Wave Mechanical Model

Im Jahr 1921 schrieb Louis de Broglie, aber keine empirischen Belege dafür, dass, wenn die Wellen haben Eigenschaften Sache dann Sache sollte Welle Eigenschaften haben. Later, Bell Labs will ensure that the de Broglie hypothesis was indeed true. De Broglie's hypothesis was a revelation that even Einstein impressed and changed the design of the atom always.

The combination of the hypothesis of Louis de Broglie's model Bohr, Erwin Schrödinger proposed the electron is a 3-D waveform around the nucleus in a wide range of wavelengths to the shape of the wave to repeat itself as a stable standing wave, what the energy levels of the Bohr model.

In support of his thesis Schrödinger developed a mathematical equation to describe the behavior of the electron wave. The Schrodinger equation was not only the correct energy levels for atomic hydrogen, but also something useful for atoms with more than one electron. This mathematical description of the details of atomic behavior has become known as "Wave mechanical model.

The atom, as we see today is mainly space with a central location, very small, dense nucleus with positively charged protons and neutral neutrons with negatively charged electrons in the energy levels in the room placed Atomic loaded.

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