Chapter+4+-+Atomic+Structure


 * Democritus' Atomic Philosophy**


 * Many consider Democritus to be the father of modern science.


 * This Greek philosopher believed that all things were made of tiny atoms, which could not be subdivided, which absolutely everything was comprised of.


 * He believed that there was only one type of atom, and that it was solid and not able to be compressed.


 * Variation occurred through the different ways the atoms could be stacked.


 * One modern issue with it is that if everything is made up of atoms, how is there dead space? Democritus answered this with his theory that there was a 'void', but Leibnitz and Einstein have been considered the two most major improvers upon Democritus' revolutionary ideas.



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[|http://www.youtube.com/v/ZnKqiojoFJU?fs=1&hl=en_US=]


 * Atom**
 * Atoms are, in fact, the building blocks of matter, which all //matter// is made up of.


 * There are 90 types of atoms that occur naturally, and scientists have been able to devise around 25 more in labs.


 * There are three types of atoms: protons, which are positively charged, electrons, which are positively charged, and neutrons, which are neutrally charged.


 * Atoms are divisible, and can be broken up into subatomic particles.


 * Protons and neutrons joined together form the nucleus of an atom.


 * Electrons are on the outside around it.



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 * Rutherford's Atomic Model**



- Experiment used to analyze the composition of atoms - Atom's mostly empty space - All positive charge, and almost all mass is in the center; the nucleus - Nucleus contains protons and neutrons - Electrons: around the nucleus and occupy most of the volume - His model can be described as a "nuclear model"

media type="youtube" key="Zd6_zVdMgJk " width="425" height="350" __Tori's Explanation of Ernest Rutherford's Discoveries __

Ernest Rutherford is not necessarily a household name, but he is considered to be the "father" of nuclear physics.

You may be asking yourself, "This man is on Australian currency, what did he do that was so fantastic?"

The answer to this, my friends, is that he discovered that the atom has a central positive nucleus surrounded by negative orbiting electrons. He created what we call the GOLD FOIL EXPERIMENT﻿. This experiment was an atom particle emitter spewing atoms at a gold piece of foil via a slit through a detecting screen.

Yeah, ok, so what's so great about that?

Well, prior to this experiment, atoms were thought to be made up of strictly electrons surrounded by a positively charged medium, thus making the atom have the same amount of positive and negative charge. When Rutherford saw that the atoms didn't directly pass through the gold foil as expected, that meant that not each atom was equally charged.

A clear picture and a video that really describes the experiment:



Here's another video that really gets the point across: