Atom+Models+(Smedile.Enrique)


 * Small, spherical, solid, indivisible model

[|www.chemistryland.com/. ../EarlyAtom.html]

Before chemistry became a big subject in the world the atom was belived to have looked like this. Depending on how many there are thing look different. The Neucleus was not descovered no electron or neutorns. **

Plum Pudding Model

[|__http://www.hcc.mnscu.edu/chem/V.08/plum_pudding_model.jpg__]

The Model was put into effect in the year 1906 showing what an atom looked like. the plumb pudding model come as one of the early assumptions of what the Atom looked like. the atom other than not having a nucleus depicts a strong argument for what an atom looks like. The positive and negative charges are represented.

Planetary Model Used in 1911

The planetary model was proposed in 1911 by British chemist Earnest Rutherford. The model consists of a tiny, dense, positively charged nucleus. Orbiting the center are negatively charged particles called electrons. It is referred to as the planetary model because of the electrons orbiting the nucleus the same way planets orbit a star. Rutherford discovered this by firing alpha particles at a piece of gold foil. The particles shot at the foil bounced back and ricocheted away from the foil. This proved that there must be a dense center of mass located within an atom.

"**Rutherford atomic model **." __Encyclopædia Britannica__. 2009. Encyclopædia Britannica Online. 02 Dec. 2009 <[|**http://www.britannica.com/EBchecked/topic/514258/Rutherford-atomic-model**]>.

Rutherford-Bohr Model Used in 1913

The Rutherford-Bohr model replaced the planetary model in 1913. The model is similar to the planetary model because it has a dense nucleus and electrons orbiting it but has some major difference. The main difference in the Rutherford-Bohr model is that electrons orbit the nucleus in specific shell. The shells explained many of the mysterious properties of the periodic table. This is because elements that have the same number of electrons in their outer most shell have similar properties. This model also explained why colors were emitted when atoms were energized. The colors came from electrons changing shells then returning to their original shell.

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Electron Cloud Model



The Electron Cloud Model is a group effort by Rutherford, Bohr, Heisenburg and Schroginer. It gathers all their studies and combines them to make this Cloud. The cloud shows the mass of electrons and the place where they belong. it all stays in place.

//Rutherford's contribution is the small dense nucleus within a cloud.// //The electron cloud surrounding it is made up by ideas form Bohr and Heisenberg.// //Bohr had the idea that electrons moved around the nucleus while Heisenberg figured out that the only way to describe where they are is through probity distribution.// //His concept is involved in quantum mechanics where Schrödinger comes into play.// //The electron cloud is a region were the electrons could be found but doesn’t specify where they are.

http://reich-chemistry.wikispaces.com/422-003+Big+Time+Line+Project + jeffrey.fortin. mark.fraser time line//