Rutherford's Atomic Model

Raisin pie-shaped atomic model proposed by Thomson in 1893 is considered very reasonable and taken for granted without any experimental test. In fact as a hypothesis, this model must go through the test. Although this is very important, but new experimental test of this hypothesis held after more than 10 years old, when in the year 1911 Geiger and Marsden, under the guidance of Rutherford's famous experiment of  particle scattering experiments.

Near the collimator of lead, Geiger and Marsden put radioactive elements as producer   ray particles with mass that is large enough and positive electric charge.  rays from a radioactive source is radiating in all directions and there's one pancarannya through slit collimator.  rays passing through this gap given the acceleration in order to penetrate the gold metal plate is very thin. Plate mounted behind the screen to capture the image. If Thomson's hypothesis is true, then the shadow will fall on a straight line behind the scenes, because the very thin gold plate  particles are accelerated to tremendous energies.

From observation it turns out that shadow  rays not only caught on the screen behind the metal pieces, but also caught on the screen on the other side and some even bounced back toward him. So  radiance, partly passed on, others have even distorted and corroded. This means that there is a fairly large positive charge that can fight coming  rays are also positively charged. The positive charge of this atom must not be located adjacent to the electrons, because if the positive charge adjacent to the core electrons of negative charge, would be neutral, and certainly not able to deflect the rays reflected even . On the basis of these data the atomic model of Rutherford as follows:

1) Atomic nuclei are composed of very dense, positively charged atoms and is the center of mass of most atoms
2) Electron located on the perimeter of the core and is relatively far from the core.
3) In order for electrons can be at a relatively far distance, the electrons must be circulated at high speed, to counteract the force pulling the nucleus, like planets around the sun.

Apparently, Rutherford planetary model was already perfect. But it turns out, a physicist named Maxwell saw a gap weakness Rutherford atomic model. According to Maxwell, is not possible electron trajectories can be outstanding with a fixed circle or ellipse shaped like planets around the sun. Why? Since according to the law of mechanics, all particles that will move the curve (either a circle or ellipse) to obtain acceleration, or acceleration. To obtain the acceleration of these particles must radiate energy. Based on this logic, then the electron energy will decrease over time, consequently the speed of orbit will gradually diminish. When the velocity diminished, the force used against the pull of the core will decrease as well. Of course, the distance to the core electrons will decrease from time to time, so that the electron trajectory can not be a circle or ellipse, but will eventually spiral to the electron will fall into the core. Maxwell's rebuttal to this, there is no satisfactory explanation of Rutherford, and this was seen as a weakness Rutherford planetary model.